Fix PanelStack

packages/core/src/components/panel-stack/panelStack.tsx

@@ -76,14 +76,17 @@ export class PanelStack extends AbstractPureComponent2<IPanelStackProps, IPanelS
 
     public componentDidUpdate(prevProps: IPanelStackProps, _prevState: IPanelStackState, _snapshot: {}) {
         super.componentDidUpdate(prevProps, _prevState, _snapshot);
+
+        // Always update local stack if stack prop changes
+        if (this.props.stack !== prevProps.stack && prevProps.stack != null) {
+            this.setState({ stack: this.props.stack.slice().reverse() });
+        }
+
+        // Only update animation direction if stack length changes
         const stackLength = this.props.stack != null ? this.props.stack.length : 0;
         const prevStackLength = prevProps.stack != null ? prevProps.stack.length : 0;
-
         if (stackLength !== prevStackLength && prevProps.stack != null) {
-            this.setState({
-                direction: prevProps.stack.length - this.props.stack.length < 0 ? "push" : "pop",
-                stack: this.props.stack.slice().reverse(),
-            });
+            this.setState({ direction: prevProps.stack.length - this.props.stack.length < 0 ? "push" : "pop" });
         }
     }