diff --git a/apps/desktop/src/plugins/hermes-bots/plugin.js b/apps/desktop/src/plugins/hermes-bots/plugin.js
index c747cf6c94..88401d2a94 100644
--- a/apps/desktop/src/plugins/hermes-bots/plugin.js
+++ b/apps/desktop/src/plugins/hermes-bots/plugin.js
@@ -9448,6 +9448,16 @@ function GroupChatWorkspace({ group, members, onBack }) {
  *  disband (or the room view's own Back) can retire the tab it opened. */
 const groupChatMainTabs = new Map()
 
+/** The in-panel room is the FALLBACK surface, not a second copy: it renders
+ *  only while no main-window tab owns the group. On desktops with the door
+ *  the room already lives in a main tab, and painting it here too produced
+ *  two live panes with independent drafts driving one shared engine (#89788).
+ *  The selection atom stays set either way so the roster row still
+ *  highlights. */
+function shouldRenderGroupChatInPane(group) {
+  return Boolean(group && !groupChatMainTabs.has(group))
+}
+
 function closeGroupChatMainTab(group) {
   const close = groupChatMainTabs.get(group)
 
@@ -9737,7 +9747,7 @@ function BotsPane() {
 
   const groupChatMembers = groupChatName ? groupChatMemberBots(groupChatName, roster, allMeta) : []
 
-  if (groupChatName && groupChatMembers.length) {
+  if (shouldRenderGroupChatInPane(groupChatName) && groupChatMembers.length) {
     return jsx(GroupChatWorkspace, { group: groupChatName, members: groupChatMembers })
   }
 
diff --git a/apps/desktop/src/plugins/hermes-bots/tests/group-chat.test.mjs b/apps/desktop/src/plugins/hermes-bots/tests/group-chat.test.mjs
index 1bacfca9ba..51780eedc4 100644
--- a/apps/desktop/src/plugins/hermes-bots/tests/group-chat.test.mjs
+++ b/apps/desktop/src/plugins/hermes-bots/tests/group-chat.test.mjs
@@ -104,7 +104,7 @@ function load(turnScript, { busyUntilResumeCall } = {}) {
     .replace(/^import .* from 'react\/jsx-runtime'\r?\n/m, '')
     .replace('export default {', 'globalThis.plugin = {')
     .concat(
-      '\nglobalThis.__gc = { sendToGroupChat, runGroupChatRounds, harvestStrandedGroupReply, resolveGroupResponders, parseGroupChatMentions, rotateGroupSpeakers, isGroupPassText, formatGroupChatLine, buildGroupChatTurnPrompt, trimGroupChatLog, disbandGroupChat, updateGroupChat, openGroupChat, closeGroupChatMainTab, $groupChats, $groupNeedsYou, $groupChatWorkspace, $botMeta, GROUP_CHAT_MAX_ROUNDS, GROUP_CHAT_MAX_MESSAGES };\n'
+      '\nglobalThis.__gc = { sendToGroupChat, runGroupChatRounds, harvestStrandedGroupReply, resolveGroupResponders, parseGroupChatMentions, rotateGroupSpeakers, isGroupPassText, formatGroupChatLine, buildGroupChatTurnPrompt, trimGroupChatLog, disbandGroupChat, updateGroupChat, openGroupChat, closeGroupChatMainTab, shouldRenderGroupChatInPane, $groupChats, $groupNeedsYou, $groupChatWorkspace, $botMeta, GROUP_CHAT_MAX_ROUNDS, GROUP_CHAT_MAX_MESSAGES };\n'
     )
   vm.runInNewContext(source, context, { filename: 'plugin.js' })
   const storageWrites = new Map()
@@ -366,9 +366,30 @@ test('group selection follows main-window open and close', () => {
 
   gc.openGroupChat('Core')
   assert.equal(gc.$groupChatWorkspace.get(), 'Core')
+  // #89788: the main tab owns the room, so the pane keeps its roster.
+  assert.equal(gc.shouldRenderGroupChatInPane('Core'), false)
 
   onClose()
   assert.equal(gc.$groupChatWorkspace.get(), null)
+  assert.equal(gc.shouldRenderGroupChatInPane('Core'), true)
+})
+
+test('older and failed workspace hosts keep the in-pane group fallback', () => {
+  const older = load(() => '(pass)')
+
+  older.openGroupChat('Core')
+  assert.equal(older.$groupChatWorkspace.get(), 'Core')
+  assert.equal(older.shouldRenderGroupChatInPane('Core'), true)
+
+  const failed = load(() => '(pass)')
+
+  failed.host.openWorkspace = () => {
+    throw new Error('workspace unavailable')
+  }
+
+  failed.openGroupChat('Ops')
+  assert.equal(failed.$groupChatWorkspace.get(), 'Ops')
+  assert.equal(failed.shouldRenderGroupChatInPane('Ops'), true)
 })
 
 test('closing an older selected group does not clear the newer selection', () => {