fix: setDepartment not persisting on chat closed

.changeset/thin-keys-impress.md

@@ -0,0 +1,5 @@
+---
+"@rocket.chat/livechat": patch
+---
+
+Fixes issue of the `setDepartment` Livechat API method not setting the store value properly (is was only setting on the guest object)

packages/livechat/src/lib/hooks.js

@@ -88,6 +88,7 @@ const api = {
 		const department = departments.find((dep) => dep._id === value || dep.name === value)?._id || '';
 
 		updateIframeGuestData({ department });
+		store.setState({ department });
 
 		if (defaultAgent && defaultAgent.department !== department) {
 			store.setState({ defaultAgent: null });