From e4da3e2ffed2b83c91d8fda56bee12251d778e32 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 03:41:21 +0000
Subject: [PATCH 01/16] test(webviews): trace columns menu chip switch target

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/test/composer-menu-dismiss.test.ts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/webviews/test/composer-menu-dismiss.test.ts b/webviews/test/composer-menu-dismiss.test.ts
index 9b5a9a27b91e..4184ad896571 100644
--- a/webviews/test/composer-menu-dismiss.test.ts
+++ b/webviews/test/composer-menu-dismiss.test.ts
@@ -248,7 +248,25 @@ await requireBrowserLane("composer-menu-dismiss.test.ts", async () => {
               expect({ from, open: await settle(page, stage.chips, [from]) }).toEqual({ from, open: [from] });
               // A menu that covers the other chip takes the press itself.
               if (await onTop(page, to)) {
+                if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model") {
+                  await page.evaluate(() => {
+                    const events = ((window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents = []);
+                    for (const type of ["pointerdown", "mousedown", "click"])
+                      document.addEventListener(
+                        type,
+                        (event) =>
+                          events.push({
+                            type,
+                            target: (event.target as Element | null)?.closest("button")?.getAttribute("aria-label"),
+                            defaultPrevented: event.defaultPrevented,
+                          }),
+                        true,
+                      );
+                  });
+                }
                 await pressAt(page, chip(to));
+                if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model")
+                  console.error("chip switch events", await page.evaluate(() => (window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents));
                 expect({ from, to, open: await settle(page, stage.chips, [to]) }).toEqual({ from, to, open: [to] });
               }
               await page.keyboard.press("Escape");

From 8259d880d339863b1588f27d5f1c96f3cffabd2f Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 03:41:21 +0000
Subject: [PATCH 02/16] test(webviews): trace columns menu chip switch target

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/test/composer-menu-dismiss.test.ts | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/webviews/test/composer-menu-dismiss.test.ts b/webviews/test/composer-menu-dismiss.test.ts
index 06a8b848e65b..d8594b526187 100644
--- a/webviews/test/composer-menu-dismiss.test.ts
+++ b/webviews/test/composer-menu-dismiss.test.ts
@@ -335,7 +335,25 @@ await requireBrowserLane("composer-menu-dismiss.test.ts", async () => {
               await menusAtRest(page);
               // A menu that covers the other chip takes the press itself.
               if (await onTop(page, to)) {
+                if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model") {
+                  await page.evaluate(() => {
+                    const events = ((window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents = []);
+                    for (const type of ["pointerdown", "mousedown", "click"])
+                      document.addEventListener(
+                        type,
+                        (event) =>
+                          events.push({
+                            type,
+                            target: (event.target as Element | null)?.closest("button")?.getAttribute("aria-label"),
+                            defaultPrevented: event.defaultPrevented,
+                          }),
+                        true,
+                      );
+                  });
+                }
                 await pressAt(page, chip(to));
+                if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model")
+                  console.error("chip switch events", await page.evaluate(() => (window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents));
                 expect({ from, to, open: await settle(page, stage.chips, [to]) }).toEqual({ from, to, open: [to] });
               }
               await page.keyboard.press("Escape");

From 1c28ed9cb79d9f16b91f38ccf8008483cdfa21ab Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:01:36 +0000
Subject: [PATCH 03/16] diagnose columns menu chip switch

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../src/agent-session/acpmux/QuickModelColumns.tsx   |  3 ++-
 webviews/test/composer-menu-dismiss.test.ts          | 12 ++++++++----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 03b3384dc5b3..966346a41689 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -977,7 +977,8 @@ function Columns({
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
           press.onPointerDown(event);
-          if (isMousePress(event)) event.preventDefault();
+          // Diagnostic candidate: leave the compatibility mouse sequence intact so a sibling
+          // popover can receive its outside-dismiss click while this chip opens.
         }}
         // The closed chip opens on ArrowDown too, as the list menu's did.
         onKeyDown={(event) => {
diff --git a/webviews/test/composer-menu-dismiss.test.ts b/webviews/test/composer-menu-dismiss.test.ts
index d8594b526187..70df99fa1594 100644
--- a/webviews/test/composer-menu-dismiss.test.ts
+++ b/webviews/test/composer-menu-dismiss.test.ts
@@ -338,15 +338,19 @@ await requireBrowserLane("composer-menu-dismiss.test.ts", async () => {
                 if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model") {
                   await page.evaluate(() => {
                     const events = ((window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents = []);
-                    for (const type of ["pointerdown", "mousedown", "click"])
+                    for (const type of ["pointerdown", "pointerup", "mousedown", "mouseup", "click", "pointercancel"])
                       document.addEventListener(
                         type,
-                        (event) =>
+                        (event) => {
+                          const button = (event.target as Element | null)?.closest<HTMLButtonElement>("button");
                           events.push({
                             type,
-                            target: (event.target as Element | null)?.closest("button")?.getAttribute("aria-label"),
+                            target: button?.getAttribute("aria-label"),
+                            connected: button?.isConnected,
                             defaultPrevented: event.defaultPrevented,
-                          }),
+                            point: document.elementFromPoint((event as PointerEvent).clientX, (event as PointerEvent).clientY)?.closest("button")?.getAttribute("aria-label"),
+                          });
+                        },
                         true,
                       );
                   });

From bcd37fa234942ac4070df5b5fdeaea426e522a14 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:27:21 +0000
Subject: [PATCH 04/16] fix(webviews): close sibling popovers for columns chip

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../agent-session/acpmux/QuickModelColumns.tsx   | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 966346a41689..69bbef4b0d81 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -10,7 +10,6 @@ import { AgentMark } from "../shared/AgentMark";
 import { Popover, type UiVirtualAnchor } from "../../ui/Popover";
 import { usePopoverTrigger } from "../../ui/popoverTrigger";
 import { DrivenList, DrivenRow, InlineCard } from "../../ui/DrivenList";
-import { isMousePress } from "../../ui/pressRelease";
 import { useOpenSide } from "../../ui/openSide";
 import { AddAccountDialog } from "./AddAccountDialog";
 import { SearchIcon, reasoningChoices, type Choice } from "./ComposerPickers";
@@ -171,6 +170,17 @@ function rowPackedToEnd(chip: HTMLElement): boolean {
   return false;
 }
 
+/** Close a sibling composer popover before the columns trigger opens its own. */
+function closeSiblingComposerPopovers(button: HTMLButtonElement) {
+  const composer = button.closest<HTMLElement>(".acpmux-composer, .nt-composer");
+  if (!composer) return;
+  for (const sibling of composer.querySelectorAll<HTMLButtonElement>(
+    '[aria-haspopup][aria-expanded="true"]',
+  )) {
+    if (sibling !== button) sibling.click();
+  }
+}
+
 function Columns({
   open,
   onOpenChange,
@@ -976,9 +986,9 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
+          closeSiblingComposerPopovers(event.currentTarget);
           press.onPointerDown(event);
-          // Diagnostic candidate: leave the compatibility mouse sequence intact so a sibling
-          // popover can receive its outside-dismiss click while this chip opens.
+          if (event.pointerType === "mouse" && event.button === 0) event.preventDefault();
         }}
         // The closed chip opens on ArrowDown too, as the list menu's did.
         onKeyDown={(event) => {

From de7f45d63d9ff13c55fc92b76172877b7aefe1a9 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:35:39 +0000
Subject: [PATCH 05/16] fix(webviews): find open sibling composer popovers

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/src/agent-session/acpmux/QuickModelColumns.tsx | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 69bbef4b0d81..d2a2df9edab3 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -172,13 +172,10 @@ function rowPackedToEnd(chip: HTMLElement): boolean {
 
 /** Close a sibling composer popover before the columns trigger opens its own. */
 function closeSiblingComposerPopovers(button: HTMLButtonElement) {
-  const composer = button.closest<HTMLElement>(".acpmux-composer, .nt-composer");
-  if (!composer) return;
-  for (const sibling of composer.querySelectorAll<HTMLButtonElement>(
+  const siblings = [...button.ownerDocument.querySelectorAll<HTMLButtonElement>(
     '[aria-haspopup][aria-expanded="true"]',
-  )) {
-    if (sibling !== button) sibling.click();
-  }
+  )].filter((sibling) => sibling !== button && sibling.closest(".acpmux-composer, .nt-composer"));
+  for (const sibling of siblings) sibling.click();
 }
 
 function Columns({

From 0c3a43cbfd9575dc52603dc9224f1e7f19769c40 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:45:05 +0000
Subject: [PATCH 06/16] fix(webviews): switch composer popovers on trigger
 press

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../acpmux/QuickModelColumns.tsx              |  9 ------
 webviews/src/ui/popoverTrigger.ts             | 32 ++++++++++++++++++-
 2 files changed, 31 insertions(+), 10 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index d2a2df9edab3..069786991806 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -170,14 +170,6 @@ function rowPackedToEnd(chip: HTMLElement): boolean {
   return false;
 }
 
-/** Close a sibling composer popover before the columns trigger opens its own. */
-function closeSiblingComposerPopovers(button: HTMLButtonElement) {
-  const siblings = [...button.ownerDocument.querySelectorAll<HTMLButtonElement>(
-    '[aria-haspopup][aria-expanded="true"]',
-  )].filter((sibling) => sibling !== button && sibling.closest(".acpmux-composer, .nt-composer"));
-  for (const sibling of siblings) sibling.click();
-}
-
 function Columns({
   open,
   onOpenChange,
@@ -983,7 +975,6 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
-          closeSiblingComposerPopovers(event.currentTarget);
           press.onPointerDown(event);
           if (event.pointerType === "mouse" && event.button === 0) event.preventDefault();
         }}
diff --git a/webviews/src/ui/popoverTrigger.ts b/webviews/src/ui/popoverTrigger.ts
index e04369c25ee3..7b66839a4899 100644
--- a/webviews/src/ui/popoverTrigger.ts
+++ b/webviews/src/ui/popoverTrigger.ts
@@ -6,7 +6,34 @@
 import { useEffect, useRef, type PointerEvent } from "react";
 import { isMousePress, trackPressRelease } from "./pressRelease";
 
+type OpenPopover = { element: HTMLElement; close(): void };
+const openPopovers = new Set<OpenPopover>();
+
+/** Close other open popovers in this composer before a trigger starts its own press. */
+function closeOpenComposerPopovers(except: HTMLElement) {
+  const composer = except.closest(".acpmux-composer, .nt-composer");
+  if (!composer) return;
+  for (const popover of [...openPopovers]) {
+    if (!popover.element.isConnected) {
+      openPopovers.delete(popover);
+      continue;
+    }
+    if (popover.element !== except && popover.element.closest(".acpmux-composer, .nt-composer") === composer)
+      popover.close();
+  }
+}
+
 export function usePopoverTrigger(open: boolean, setOpen: (open: boolean) => void, show?: () => void) {
+  const targetRef = useRef<HTMLElement | null>(null);
+  const setOpenRef = useRef(setOpen);
+  setOpenRef.current = setOpen;
+  useEffect(() => {
+    const element = targetRef.current;
+    if (!open || !element) return;
+    const popover = { element, close: () => setOpenRef.current(false) };
+    openPopovers.add(popover);
+    return () => openPopovers.delete(popover);
+  }, [open]);
   const openAtPress = useRef<boolean | undefined>(undefined);
   // A mouse press already opened or closed it: the click it ends with does nothing.
   const pressed = useRef(false);
@@ -22,6 +49,8 @@ export function usePopoverTrigger(open: boolean, setOpen: (open: boolean) => voi
   );
   return {
     onPointerDown: (event: PointerEvent<HTMLElement>) => {
+      targetRef.current = event.currentTarget;
+      closeOpenComposerPopovers(event.currentTarget);
       openAtPress.current = open;
       if (!isMousePress(event)) return;
       // Opening a menu moves focus into it, and the browser's transient :active state goes with it
@@ -63,7 +92,8 @@ export function usePopoverTrigger(open: boolean, setOpen: (open: boolean) => voi
     onMouseDown: (event: { preventDefault(): void }) => {
       if (open) event.preventDefault();
     },
-    onClick: () => {
+    onClick: (event: { currentTarget: HTMLElement }) => {
+      targetRef.current = event.currentTarget;
       const wasOpen = openAtPress.current ?? open;
       openAtPress.current = undefined;
       if (pressed.current) {

From 6774e5515197ef67524acc179f6d7b60ad0cacaf Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:51:20 +0000
Subject: [PATCH 07/16] Revert "fix(webviews): switch composer popovers on
 trigger press"

This reverts commit 0c3a43cbfd9575dc52603dc9224f1e7f19769c40.

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../acpmux/QuickModelColumns.tsx              |  9 ++++++
 webviews/src/ui/popoverTrigger.ts             | 32 +------------------
 2 files changed, 10 insertions(+), 31 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 069786991806..d2a2df9edab3 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -170,6 +170,14 @@ function rowPackedToEnd(chip: HTMLElement): boolean {
   return false;
 }
 
+/** Close a sibling composer popover before the columns trigger opens its own. */
+function closeSiblingComposerPopovers(button: HTMLButtonElement) {
+  const siblings = [...button.ownerDocument.querySelectorAll<HTMLButtonElement>(
+    '[aria-haspopup][aria-expanded="true"]',
+  )].filter((sibling) => sibling !== button && sibling.closest(".acpmux-composer, .nt-composer"));
+  for (const sibling of siblings) sibling.click();
+}
+
 function Columns({
   open,
   onOpenChange,
@@ -975,6 +983,7 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
+          closeSiblingComposerPopovers(event.currentTarget);
           press.onPointerDown(event);
           if (event.pointerType === "mouse" && event.button === 0) event.preventDefault();
         }}
diff --git a/webviews/src/ui/popoverTrigger.ts b/webviews/src/ui/popoverTrigger.ts
index 7b66839a4899..e04369c25ee3 100644
--- a/webviews/src/ui/popoverTrigger.ts
+++ b/webviews/src/ui/popoverTrigger.ts
@@ -6,34 +6,7 @@
 import { useEffect, useRef, type PointerEvent } from "react";
 import { isMousePress, trackPressRelease } from "./pressRelease";
 
-type OpenPopover = { element: HTMLElement; close(): void };
-const openPopovers = new Set<OpenPopover>();
-
-/** Close other open popovers in this composer before a trigger starts its own press. */
-function closeOpenComposerPopovers(except: HTMLElement) {
-  const composer = except.closest(".acpmux-composer, .nt-composer");
-  if (!composer) return;
-  for (const popover of [...openPopovers]) {
-    if (!popover.element.isConnected) {
-      openPopovers.delete(popover);
-      continue;
-    }
-    if (popover.element !== except && popover.element.closest(".acpmux-composer, .nt-composer") === composer)
-      popover.close();
-  }
-}
-
 export function usePopoverTrigger(open: boolean, setOpen: (open: boolean) => void, show?: () => void) {
-  const targetRef = useRef<HTMLElement | null>(null);
-  const setOpenRef = useRef(setOpen);
-  setOpenRef.current = setOpen;
-  useEffect(() => {
-    const element = targetRef.current;
-    if (!open || !element) return;
-    const popover = { element, close: () => setOpenRef.current(false) };
-    openPopovers.add(popover);
-    return () => openPopovers.delete(popover);
-  }, [open]);
   const openAtPress = useRef<boolean | undefined>(undefined);
   // A mouse press already opened or closed it: the click it ends with does nothing.
   const pressed = useRef(false);
@@ -49,8 +22,6 @@ export function usePopoverTrigger(open: boolean, setOpen: (open: boolean) => voi
   );
   return {
     onPointerDown: (event: PointerEvent<HTMLElement>) => {
-      targetRef.current = event.currentTarget;
-      closeOpenComposerPopovers(event.currentTarget);
       openAtPress.current = open;
       if (!isMousePress(event)) return;
       // Opening a menu moves focus into it, and the browser's transient :active state goes with it
@@ -92,8 +63,7 @@ export function usePopoverTrigger(open: boolean, setOpen: (open: boolean) => voi
     onMouseDown: (event: { preventDefault(): void }) => {
       if (open) event.preventDefault();
     },
-    onClick: (event: { currentTarget: HTMLElement }) => {
-      targetRef.current = event.currentTarget;
+    onClick: () => {
       const wasOpen = openAtPress.current ?? open;
       openAtPress.current = undefined;
       if (pressed.current) {

From 47fa21f216508fa22ca9c32b7b2baae47d807cdf Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:52:52 +0000
Subject: [PATCH 08/16] fix(webviews): close folder on columns trigger press

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/src/agent-session/acpmux/FolderPopover.tsx  | 11 +++++++++++
 .../src/agent-session/acpmux/QuickModelColumns.tsx   | 12 +++---------
 2 files changed, 14 insertions(+), 9 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/FolderPopover.tsx b/webviews/src/agent-session/acpmux/FolderPopover.tsx
index a2284071a1e4..48a1892c165f 100644
--- a/webviews/src/agent-session/acpmux/FolderPopover.tsx
+++ b/webviews/src/agent-session/acpmux/FolderPopover.tsx
@@ -171,6 +171,17 @@ export function FolderPopover({
     if (escaped.current) trigger.current?.focus();
     escaped.current = false;
   };
+  useEffect(() => {
+    if (!open) return;
+    const switchPopover = (event: Event) => {
+      const target = (event as CustomEvent<unknown>).detail;
+      if (!(target instanceof Element)) return;
+      if (target.closest(".acpmux-composer, .nt-composer") === trigger.current?.closest(".acpmux-composer, .nt-composer"))
+        close();
+    };
+    document.addEventListener("cmux-composer-popover-switch", switchPopover);
+    return () => document.removeEventListener("cmux-composer-popover-switch", switchPopover);
+  }, [open, close]);
   const submit = (value: string) => {
     // Add folder… keeps the menu open: its list now adds a folder.
     if (value === ACTION_EXTRA) {
diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index d2a2df9edab3..aeccbdaa506b 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -170,14 +170,6 @@ function rowPackedToEnd(chip: HTMLElement): boolean {
   return false;
 }
 
-/** Close a sibling composer popover before the columns trigger opens its own. */
-function closeSiblingComposerPopovers(button: HTMLButtonElement) {
-  const siblings = [...button.ownerDocument.querySelectorAll<HTMLButtonElement>(
-    '[aria-haspopup][aria-expanded="true"]',
-  )].filter((sibling) => sibling !== button && sibling.closest(".acpmux-composer, .nt-composer"));
-  for (const sibling of siblings) sibling.click();
-}
-
 function Columns({
   open,
   onOpenChange,
@@ -983,7 +975,9 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
-          closeSiblingComposerPopovers(event.currentTarget);
+          event.currentTarget.ownerDocument.dispatchEvent(
+            new CustomEvent("cmux-composer-popover-switch", { detail: event.currentTarget }),
+          );
           press.onPointerDown(event);
           if (event.pointerType === "mouse" && event.button === 0) event.preventDefault();
         }}

From 9b2192c00f61a67f0c3c552650b6b8e01807914a Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:55:25 +0000
Subject: [PATCH 09/16] test(webviews): remove temporary pointer trace

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/test/composer-menu-dismiss.test.ts | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/webviews/test/composer-menu-dismiss.test.ts b/webviews/test/composer-menu-dismiss.test.ts
index 70df99fa1594..d8594b526187 100644
--- a/webviews/test/composer-menu-dismiss.test.ts
+++ b/webviews/test/composer-menu-dismiss.test.ts
@@ -338,19 +338,15 @@ await requireBrowserLane("composer-menu-dismiss.test.ts", async () => {
                 if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model") {
                   await page.evaluate(() => {
                     const events = ((window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents = []);
-                    for (const type of ["pointerdown", "pointerup", "mousedown", "mouseup", "click", "pointercancel"])
+                    for (const type of ["pointerdown", "mousedown", "click"])
                       document.addEventListener(
                         type,
-                        (event) => {
-                          const button = (event.target as Element | null)?.closest<HTMLButtonElement>("button");
+                        (event) =>
                           events.push({
                             type,
-                            target: button?.getAttribute("aria-label"),
-                            connected: button?.isConnected,
+                            target: (event.target as Element | null)?.closest("button")?.getAttribute("aria-label"),
                             defaultPrevented: event.defaultPrevented,
-                            point: document.elementFromPoint((event as PointerEvent).clientX, (event as PointerEvent).clientY)?.closest("button")?.getAttribute("aria-label"),
-                          });
-                        },
+                          }),
                         true,
                       );
                   });

From b205f0042454bb872fca58337292ad746a75888f Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 05:57:14 +0000
Subject: [PATCH 10/16] style(webviews): wrap folder popover switch guard

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/src/agent-session/acpmux/FolderPopover.tsx | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/webviews/src/agent-session/acpmux/FolderPopover.tsx b/webviews/src/agent-session/acpmux/FolderPopover.tsx
index 48a1892c165f..2dfacf6e0114 100644
--- a/webviews/src/agent-session/acpmux/FolderPopover.tsx
+++ b/webviews/src/agent-session/acpmux/FolderPopover.tsx
@@ -176,7 +176,10 @@ export function FolderPopover({
     const switchPopover = (event: Event) => {
       const target = (event as CustomEvent<unknown>).detail;
       if (!(target instanceof Element)) return;
-      if (target.closest(".acpmux-composer, .nt-composer") === trigger.current?.closest(".acpmux-composer, .nt-composer"))
+      if (
+        target.closest(".acpmux-composer, .nt-composer") ===
+        trigger.current?.closest(".acpmux-composer, .nt-composer")
+      )
         close();
     };
     document.addEventListener("cmux-composer-popover-switch", switchPopover);

From c88011e6d1a610b8fe29c42a763713e9fff108f2 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 06:00:50 +0000
Subject: [PATCH 11/16] style(webviews): retain shared mouse press check

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/src/agent-session/acpmux/QuickModelColumns.tsx | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index aeccbdaa506b..25940da70e15 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -10,6 +10,7 @@ import { AgentMark } from "../shared/AgentMark";
 import { Popover, type UiVirtualAnchor } from "../../ui/Popover";
 import { usePopoverTrigger } from "../../ui/popoverTrigger";
 import { DrivenList, DrivenRow, InlineCard } from "../../ui/DrivenList";
+import { isMousePress } from "../../ui/pressRelease";
 import { useOpenSide } from "../../ui/openSide";
 import { AddAccountDialog } from "./AddAccountDialog";
 import { SearchIcon, reasoningChoices, type Choice } from "./ComposerPickers";
@@ -979,7 +980,7 @@ function Columns({
             new CustomEvent("cmux-composer-popover-switch", { detail: event.currentTarget }),
           );
           press.onPointerDown(event);
-          if (event.pointerType === "mouse" && event.button === 0) event.preventDefault();
+          if (isMousePress(event)) event.preventDefault();
         }}
         // The closed chip opens on ArrowDown too, as the list menu's did.
         onKeyDown={(event) => {

From 367076998b5ff8496c4babeaea3d775220b6c987 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 06:09:02 +0000
Subject: [PATCH 12/16] fix(webviews): remove diagnostic switch trace

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../src/agent-session/acpmux/FolderPopover.tsx |  7 +++----
 webviews/test/composer-menu-dismiss.test.ts    | 18 ------------------
 2 files changed, 3 insertions(+), 22 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/FolderPopover.tsx b/webviews/src/agent-session/acpmux/FolderPopover.tsx
index 2dfacf6e0114..6c9a557e1368 100644
--- a/webviews/src/agent-session/acpmux/FolderPopover.tsx
+++ b/webviews/src/agent-session/acpmux/FolderPopover.tsx
@@ -176,10 +176,9 @@ export function FolderPopover({
     const switchPopover = (event: Event) => {
       const target = (event as CustomEvent<unknown>).detail;
       if (!(target instanceof Element)) return;
-      if (
-        target.closest(".acpmux-composer, .nt-composer") ===
-        trigger.current?.closest(".acpmux-composer, .nt-composer")
-      )
+      const targetComposer = target.closest(".acpmux-composer, .nt-composer");
+      const folderComposer = trigger.current?.closest(".acpmux-composer, .nt-composer");
+      if (targetComposer && targetComposer === folderComposer)
         close();
     };
     document.addEventListener("cmux-composer-popover-switch", switchPopover);
diff --git a/webviews/test/composer-menu-dismiss.test.ts b/webviews/test/composer-menu-dismiss.test.ts
index d8594b526187..06a8b848e65b 100644
--- a/webviews/test/composer-menu-dismiss.test.ts
+++ b/webviews/test/composer-menu-dismiss.test.ts
@@ -335,25 +335,7 @@ await requireBrowserLane("composer-menu-dismiss.test.ts", async () => {
               await menusAtRest(page);
               // A menu that covers the other chip takes the press itself.
               if (await onTop(page, to)) {
-                if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model") {
-                  await page.evaluate(() => {
-                    const events = ((window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents = []);
-                    for (const type of ["pointerdown", "mousedown", "click"])
-                      document.addEventListener(
-                        type,
-                        (event) =>
-                          events.push({
-                            type,
-                            target: (event.target as Element | null)?.closest("button")?.getAttribute("aria-label"),
-                            defaultPrevented: event.defaultPrevented,
-                          }),
-                        true,
-                      );
-                  });
-                }
                 await pressAt(page, chip(to));
-                if (stage.variant === "new-chat-reasoning" && width === 760 && from === "Folder" && to === "Model")
-                  console.error("chip switch events", await page.evaluate(() => (window as unknown as { chipSwitchEvents?: unknown[] }).chipSwitchEvents));
                 expect({ from, to, open: await settle(page, stage.chips, [to]) }).toEqual({ from, to, open: [to] });
               }
               await page.keyboard.press("Escape");

From b85cc637375767d3430213a0c631f6191d1dd3ff Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 06:14:28 +0000
Subject: [PATCH 13/16] docs(webviews): explain composer popover switch

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/src/agent-session/acpmux/QuickModelColumns.tsx | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 25940da70e15..9c6d5f494ae1 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -976,6 +976,8 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
+          // A sibling composer popover can consume the compatibility click while it dismisses;
+          // close its React state while this trigger is still the stable pointer target.
           event.currentTarget.ownerDocument.dispatchEvent(
             new CustomEvent("cmux-composer-popover-switch", { detail: event.currentTarget }),
           );

From 200851cbaf781b28bb731f14d3a91f1cc32456cc Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 06:56:39 +0000
Subject: [PATCH 14/16] fix(webviews): close both folder picker variants on
 model press

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../agent-session/acpmux/ComposerContext.tsx  |  3 ++-
 .../agent-session/acpmux/FolderPopover.tsx    | 16 ++-----------
 .../acpmux/QuickModelColumns.tsx              |  4 ++--
 .../agent-session/acpmux/locationPopover.ts   | 24 ++++++++++++++++++-
 4 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/ComposerContext.tsx b/webviews/src/agent-session/acpmux/ComposerContext.tsx
index cbf1ceb722cf..d2a06eded4d3 100644
--- a/webviews/src/agent-session/acpmux/ComposerContext.tsx
+++ b/webviews/src/agent-session/acpmux/ComposerContext.tsx
@@ -56,7 +56,7 @@ import { projectSuffixes } from "./projectSuffix";
 import { belowCheckout, folderRepo, isMainCheckout, worktreeName, type ProjectRepo } from "./projectRepos";
 import { isAgentHome, projectLabel } from "./sessionList";
 import { translate as t, useT } from "./i18n";
-import { useLocationOpener, useLocationPopover } from "./locationPopover";
+import { useComposerPopoverSwitch, useLocationOpener, useLocationPopover } from "./locationPopover";
 import { usePopoverTrigger } from "../../ui/popoverTrigger";
 import { focusAfterEscape } from "../../ui/escapeFocus";
 import type { RunModeRows } from "./sandboxRun";
@@ -1262,6 +1262,7 @@ function LocationPicker({
   };
   const press = usePopoverTrigger(open, changeOpen);
   const trigger = useRef<HTMLButtonElement>(null);
+  useComposerPopoverSwitch(open, trigger, () => changeOpen(false));
   useLocationOpener(disabled ? undefined : menu, () => setOpen(true));
   useEffect(() => {
     if (!closeOnTrustAsk || !open) return;
diff --git a/webviews/src/agent-session/acpmux/FolderPopover.tsx b/webviews/src/agent-session/acpmux/FolderPopover.tsx
index 6c9a557e1368..0d27aa172861 100644
--- a/webviews/src/agent-session/acpmux/FolderPopover.tsx
+++ b/webviews/src/agent-session/acpmux/FolderPopover.tsx
@@ -6,7 +6,7 @@ import { AddProjectDialog, type BrowseRequest, type BrowseResult } from "./AddPr
 import { ExtraFolderList } from "./ExtraFolderList";
 import type { ExtraFolderRows } from "./extraFolders";
 import { translate as t } from "./i18n";
-import { useLocationOpener, useLocationPopover } from "./locationPopover";
+import { useComposerPopoverSwitch, useLocationOpener, useLocationPopover } from "./locationPopover";
 import { ProjectBadge } from "./ProjectBadge";
 import { projectSuffixes } from "./projectSuffix";
 import { folderRepo, groupByRepo, isMainCheckout, shownRepoRows, worktreeName, type ProjectRepo } from "./projectRepos";
@@ -171,19 +171,7 @@ export function FolderPopover({
     if (escaped.current) trigger.current?.focus();
     escaped.current = false;
   };
-  useEffect(() => {
-    if (!open) return;
-    const switchPopover = (event: Event) => {
-      const target = (event as CustomEvent<unknown>).detail;
-      if (!(target instanceof Element)) return;
-      const targetComposer = target.closest(".acpmux-composer, .nt-composer");
-      const folderComposer = trigger.current?.closest(".acpmux-composer, .nt-composer");
-      if (targetComposer && targetComposer === folderComposer)
-        close();
-    };
-    document.addEventListener("cmux-composer-popover-switch", switchPopover);
-    return () => document.removeEventListener("cmux-composer-popover-switch", switchPopover);
-  }, [open, close]);
+  useComposerPopoverSwitch(open, trigger, close);
   const submit = (value: string) => {
     // Add folder… keeps the menu open: its list now adds a folder.
     if (value === ACTION_EXTRA) {
diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 9c6d5f494ae1..9015682fe33c 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -976,8 +976,8 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
-          // A sibling composer popover can consume the compatibility click while it dismisses;
-          // close its React state while this trigger is still the stable pointer target.
+          // The compatibility click can be lost after opening the columns on pointerdown.
+          // Close the sibling location menu before opening and focusing this one.
           event.currentTarget.ownerDocument.dispatchEvent(
             new CustomEvent("cmux-composer-popover-switch", { detail: event.currentTarget }),
           );
diff --git a/webviews/src/agent-session/acpmux/locationPopover.ts b/webviews/src/agent-session/acpmux/locationPopover.ts
index e3848fb1c2dd..5f1e1ecb48c1 100644
--- a/webviews/src/agent-session/acpmux/locationPopover.ts
+++ b/webviews/src/agent-session/acpmux/locationPopover.ts
@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState, type RefObject } from "react";
 import type { UiVirtualAnchor } from "../../ui/Popover";
 import { useOpenSide, type UiPopupFlip, type UiPopupSide } from "../../ui/openSide";
 import { registerPicker } from "./pickerOpeners";
@@ -6,6 +6,28 @@ import { registerPicker } from "./pickerOpeners";
 /// The composer a location control heads: the chat pane's form, or the New Tab page's composer.
 const COMPOSER = "form.acpmux-composer, .nt-composer";
 
+/** Close a location menu before the columns model chip opens on the same pointer press. */
+export function useComposerPopoverSwitch(
+  open: boolean,
+  trigger: RefObject<HTMLElement | null>,
+  close: () => void,
+) {
+  const latestClose = useRef(close);
+  latestClose.current = close;
+  useEffect(() => {
+    const doc = trigger.current?.ownerDocument;
+    if (!open || !doc) return;
+    const switchPopover = (event: Event) => {
+      const target = (event as CustomEvent<unknown>).detail;
+      if (!(target instanceof Element)) return;
+      const composer = trigger.current?.closest(COMPOSER);
+      if (composer && target.closest(COMPOSER) === composer) latestClose.current();
+    };
+    doc.addEventListener("cmux-composer-popover-switch", switchPopover);
+    return () => doc.removeEventListener("cmux-composer-popover-switch", switchPopover);
+  }, [open, trigger]);
+}
+
 /// The side away from the conversation (Leo 2026-10-29: "make them open away from teh chat, which
 /// is obviously up if it's up, down if it's down"). It is read from where the composer sits in the
 /// window when the menu opens, never from which page it is: a composer in the lower half has the

From 5a4bcd36659624938209a3c65d5e257c3f020ca6 Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 07:20:36 +0000
Subject: [PATCH 15/16] style(webviews): format composer popover switch hook

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 webviews/src/agent-session/acpmux/locationPopover.ts | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/locationPopover.ts b/webviews/src/agent-session/acpmux/locationPopover.ts
index 5f1e1ecb48c1..b67121e14172 100644
--- a/webviews/src/agent-session/acpmux/locationPopover.ts
+++ b/webviews/src/agent-session/acpmux/locationPopover.ts
@@ -7,11 +7,7 @@ import { registerPicker } from "./pickerOpeners";
 const COMPOSER = "form.acpmux-composer, .nt-composer";
 
 /** Close a location menu before the columns model chip opens on the same pointer press. */
-export function useComposerPopoverSwitch(
-  open: boolean,
-  trigger: RefObject<HTMLElement | null>,
-  close: () => void,
-) {
+export function useComposerPopoverSwitch(open: boolean, trigger: RefObject<HTMLElement | null>, close: () => void) {
   const latestClose = useRef(close);
   latestClose.current = close;
   useEffect(() => {

From 4ac197e6887382445560055e9d4eee1ed32cae1d Mon Sep 17 00:00:00 2001
From: Leo Li <cheerleaderleo@outlook.com>
Date: Wed, 4 Nov 2026 07:40:04 +0000
Subject: [PATCH 16/16] fix(webviews): keep model columns trigger mounted
 before opening

Co-authored-by: Codex <199175422+chatgpt-codex-connector[bot]@users.noreply.github.com>
Agent-Session: https://cmux.com/deeplink/agent?id=aid-c05f94d269ac08017254
---
 .../agent-session/acpmux/ComposerContext.tsx  |  3 +--
 .../agent-session/acpmux/FolderPopover.tsx    |  3 +--
 .../src/agent-session/acpmux/ModelPicker.tsx  |  6 +++++-
 .../acpmux/QuickModelColumns.tsx              |  5 -----
 .../agent-session/acpmux/locationPopover.ts   | 20 +------------------
 5 files changed, 8 insertions(+), 29 deletions(-)

diff --git a/webviews/src/agent-session/acpmux/ComposerContext.tsx b/webviews/src/agent-session/acpmux/ComposerContext.tsx
index d2a06eded4d3..cbf1ceb722cf 100644
--- a/webviews/src/agent-session/acpmux/ComposerContext.tsx
+++ b/webviews/src/agent-session/acpmux/ComposerContext.tsx
@@ -56,7 +56,7 @@ import { projectSuffixes } from "./projectSuffix";
 import { belowCheckout, folderRepo, isMainCheckout, worktreeName, type ProjectRepo } from "./projectRepos";
 import { isAgentHome, projectLabel } from "./sessionList";
 import { translate as t, useT } from "./i18n";
-import { useComposerPopoverSwitch, useLocationOpener, useLocationPopover } from "./locationPopover";
+import { useLocationOpener, useLocationPopover } from "./locationPopover";
 import { usePopoverTrigger } from "../../ui/popoverTrigger";
 import { focusAfterEscape } from "../../ui/escapeFocus";
 import type { RunModeRows } from "./sandboxRun";
@@ -1262,7 +1262,6 @@ function LocationPicker({
   };
   const press = usePopoverTrigger(open, changeOpen);
   const trigger = useRef<HTMLButtonElement>(null);
-  useComposerPopoverSwitch(open, trigger, () => changeOpen(false));
   useLocationOpener(disabled ? undefined : menu, () => setOpen(true));
   useEffect(() => {
     if (!closeOnTrustAsk || !open) return;
diff --git a/webviews/src/agent-session/acpmux/FolderPopover.tsx b/webviews/src/agent-session/acpmux/FolderPopover.tsx
index 0d27aa172861..a2284071a1e4 100644
--- a/webviews/src/agent-session/acpmux/FolderPopover.tsx
+++ b/webviews/src/agent-session/acpmux/FolderPopover.tsx
@@ -6,7 +6,7 @@ import { AddProjectDialog, type BrowseRequest, type BrowseResult } from "./AddPr
 import { ExtraFolderList } from "./ExtraFolderList";
 import type { ExtraFolderRows } from "./extraFolders";
 import { translate as t } from "./i18n";
-import { useComposerPopoverSwitch, useLocationOpener, useLocationPopover } from "./locationPopover";
+import { useLocationOpener, useLocationPopover } from "./locationPopover";
 import { ProjectBadge } from "./ProjectBadge";
 import { projectSuffixes } from "./projectSuffix";
 import { folderRepo, groupByRepo, isMainCheckout, shownRepoRows, worktreeName, type ProjectRepo } from "./projectRepos";
@@ -171,7 +171,6 @@ export function FolderPopover({
     if (escaped.current) trigger.current?.focus();
     escaped.current = false;
   };
-  useComposerPopoverSwitch(open, trigger, close);
   const submit = (value: string) => {
     // Add folder… keeps the menu open: its list now adds a folder.
     if (value === ACTION_EXTRA) {
diff --git a/webviews/src/agent-session/acpmux/ModelPicker.tsx b/webviews/src/agent-session/acpmux/ModelPicker.tsx
index 022b6d30c82f..c73451a3c884 100644
--- a/webviews/src/agent-session/acpmux/ModelPicker.tsx
+++ b/webviews/src/agent-session/acpmux/ModelPicker.tsx
@@ -931,7 +931,11 @@ export function ModelPicker(props: ModelPickerProps) {
     // opens the full picker, which has no rail either.
     // A folder profile is a machine choice, so its current models stay in the plain compact list
     // while the harness-only rail remains absent.
-    if (!modelsNeeded || !quick || (harnessFixed && !fork) || current?.folder) return undefined;
+    if (!quick || (harnessFixed && !fork) || current?.folder) return undefined;
+    // Keep the columns trigger mounted before its first press. Replacing the list trigger as it
+    // opens loses that press's click, so another popover never receives its outside dismissal.
+    // The rows stay lazy until the picker opens.
+    if (!modelsNeeded) return [];
     const row = (entry: HarnessChoice, model: ModelChoice) => quickRow(entry.id, model);
     // A started chat that forks lists every harness, as a New Tab does; its own stays the chat's.
     const startable = (fork ? allHarnesses : harnesses).filter(
diff --git a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
index 9015682fe33c..03b3384dc5b3 100644
--- a/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
+++ b/webviews/src/agent-session/acpmux/QuickModelColumns.tsx
@@ -976,11 +976,6 @@ function Columns({
         // A mouse press never focuses the chip, as the list menu's button: a press that closes the
         // menu and lands a pick leaves the keyboard in the prompt the picker focused.
         onPointerDown={(event) => {
-          // The compatibility click can be lost after opening the columns on pointerdown.
-          // Close the sibling location menu before opening and focusing this one.
-          event.currentTarget.ownerDocument.dispatchEvent(
-            new CustomEvent("cmux-composer-popover-switch", { detail: event.currentTarget }),
-          );
           press.onPointerDown(event);
           if (isMousePress(event)) event.preventDefault();
         }}
diff --git a/webviews/src/agent-session/acpmux/locationPopover.ts b/webviews/src/agent-session/acpmux/locationPopover.ts
index b67121e14172..e3848fb1c2dd 100644
--- a/webviews/src/agent-session/acpmux/locationPopover.ts
+++ b/webviews/src/agent-session/acpmux/locationPopover.ts
@@ -1,4 +1,4 @@
-import { useCallback, useEffect, useMemo, useRef, useState, type RefObject } from "react";
+import { useCallback, useEffect, useMemo, useRef, useState } from "react";
 import type { UiVirtualAnchor } from "../../ui/Popover";
 import { useOpenSide, type UiPopupFlip, type UiPopupSide } from "../../ui/openSide";
 import { registerPicker } from "./pickerOpeners";
@@ -6,24 +6,6 @@ import { registerPicker } from "./pickerOpeners";
 /// The composer a location control heads: the chat pane's form, or the New Tab page's composer.
 const COMPOSER = "form.acpmux-composer, .nt-composer";
 
-/** Close a location menu before the columns model chip opens on the same pointer press. */
-export function useComposerPopoverSwitch(open: boolean, trigger: RefObject<HTMLElement | null>, close: () => void) {
-  const latestClose = useRef(close);
-  latestClose.current = close;
-  useEffect(() => {
-    const doc = trigger.current?.ownerDocument;
-    if (!open || !doc) return;
-    const switchPopover = (event: Event) => {
-      const target = (event as CustomEvent<unknown>).detail;
-      if (!(target instanceof Element)) return;
-      const composer = trigger.current?.closest(COMPOSER);
-      if (composer && target.closest(COMPOSER) === composer) latestClose.current();
-    };
-    doc.addEventListener("cmux-composer-popover-switch", switchPopover);
-    return () => doc.removeEventListener("cmux-composer-popover-switch", switchPopover);
-  }, [open, trigger]);
-}
-
 /// The side away from the conversation (Leo 2026-10-29: "make them open away from teh chat, which
 /// is obviously up if it's up, down if it's down"). It is read from where the composer sits in the
 /// window when the menu opens, never from which page it is: a composer in the lower half has the