diff --git a/src/components/conversations/conversation-detail-panel.tsx b/src/components/conversations/conversation-detail-panel.tsx
index 64481bd..8d92dd3 100644
--- a/src/components/conversations/conversation-detail-panel.tsx
+++ b/src/components/conversations/conversation-detail-panel.tsx
@@ -964,7 +964,33 @@ export function ConversationDetailPanel() {
     })
   }, [onPreviewTabReplaced, disconnectByKey])
 
-  // Background turn_complete handler: for conversations not open in tabs
+  // Refs for background turn_complete handler so the listener
+  // can be registered once and always read the latest values.
+  const getConversationIdByExternalIdRef = useRef(getConversationIdByExternalId)
+  const getSessionRef = useRef(getSession)
+  const runtimeCompleteTurnRef = useRef(runtimeCompleteTurn)
+  const runtimeRemoveConversationRef = useRef(runtimeRemoveConversation)
+  const refreshConversationsRef = useRef(refreshConversations)
+  useEffect(() => {
+    getConversationIdByExternalIdRef.current = getConversationIdByExternalId
+  }, [getConversationIdByExternalId])
+  useEffect(() => {
+    getSessionRef.current = getSession
+  }, [getSession])
+  useEffect(() => {
+    runtimeCompleteTurnRef.current = runtimeCompleteTurn
+  }, [runtimeCompleteTurn])
+  useEffect(() => {
+    runtimeRemoveConversationRef.current = runtimeRemoveConversation
+  }, [runtimeRemoveConversation])
+  useEffect(() => {
+    refreshConversationsRef.current = refreshConversations
+  }, [refreshConversations])
+
+  // Background turn_complete handler: for conversations not open in tabs.
+  // Registered once — uses refs to avoid re-creating the listener on every
+  // state change, which would cause "Couldn't find callback id" warnings
+  // due to the async gap between unlisten and the new listen().
   useEffect(() => {
     let cancelled = false
     let unlisten: (() => void | Promise<void>) | null = null
@@ -975,9 +1001,8 @@ export function ConversationDetailPanel() {
           const payload = event.payload
           if (payload.type !== "turn_complete") return
 
-          const runtimeConversationId = getConversationIdByExternalId(
-            payload.session_id
-          )
+          const runtimeConversationId =
+            getConversationIdByExternalIdRef.current(payload.session_id)
           const summary = conversationsRef.current.find(
             (item) => item.external_id === payload.session_id
           )
@@ -997,12 +1022,12 @@ export function ConversationDetailPanel() {
           if (isOpenInTabs) return
 
           // Promote liveMessage + optimisticTurns to localTurns immediately
-          runtimeCompleteTurn(matchedConversationId)
+          runtimeCompleteTurnRef.current(matchedConversationId)
 
           // If tab was closed while agent was responding, clean up now
-          const session = getSession(matchedConversationId)
+          const session = getSessionRef.current(matchedConversationId)
           if (session?.pendingCleanup) {
-            runtimeRemoveConversation(matchedConversationId)
+            runtimeRemoveConversationRef.current(matchedConversationId)
           }
 
           // Update conversation status — use the DB summary (found by
@@ -1013,7 +1038,7 @@ export function ConversationDetailPanel() {
             (matchedConversationId > 0 ? matchedConversationId : null)
           if (dbId && (!summary || summary.status === "in_progress")) {
             updateConversationStatus(dbId, "pending_review")
-              .then(() => refreshConversations())
+              .then(() => refreshConversationsRef.current())
               .catch((error: unknown) =>
                 console.error(
                   "[ConversationDetailPanel] background update status:",
@@ -1044,13 +1069,7 @@ export function ConversationDetailPanel() {
         "ConversationDetailPanel.backgroundRefresh"
       )
     }
-  }, [
-    getConversationIdByExternalId,
-    getSession,
-    runtimeCompleteTurn,
-    runtimeRemoveConversation,
-    refreshConversations,
-  ])
+  }, [])
 
   const hasNoTabs = tabs.length === 0 && !activeTabId
   const activeConversationTab = useMemo(
diff --git a/src/contexts/acp-connections-context.tsx b/src/contexts/acp-connections-context.tsx
index 9241805..1f923ed 100644
--- a/src/contexts/acp-connections-context.tsx
+++ b/src/contexts/acp-connections-context.tsx
@@ -1149,6 +1149,8 @@ export function AcpConnectionsProvider({ children }: { children: ReactNode }) {
 
   // Guard against concurrent connect() calls
   const connectingKeysRef = useRef(new Set<string>())
+  // Keys whose disconnect was requested while connect was still in flight
+  const abandonedKeysRef = useRef(new Set<string>())
 
   type AutoLinkBlockState =
     | { kind: "none"; reason: "" }
@@ -1772,6 +1774,14 @@ export function AcpConnectionsProvider({ children }: { children: ReactNode }) {
 
         await waitForListenerReady()
         const connectionId = await acpConnect(agentType, workingDir, sessionId)
+
+        // If disconnect was requested while connect was in flight,
+        // tear down immediately instead of registering the connection.
+        if (abandonedKeysRef.current.delete(contextKey)) {
+          acpDisconnect(connectionId).catch(() => {})
+          return
+        }
+
         reverseMapRef.current.set(connectionId, contextKey)
         lastActivityRef.current.set(contextKey, Date.now())
         dispatch({
@@ -1800,6 +1810,7 @@ export function AcpConnectionsProvider({ children }: { children: ReactNode }) {
         throw err
       } finally {
         connectingKeysRef.current.delete(contextKey)
+        abandonedKeysRef.current.delete(contextKey)
       }
     },
     [
@@ -1816,7 +1827,14 @@ export function AcpConnectionsProvider({ children }: { children: ReactNode }) {
   const disconnect = useCallback(
     async (contextKey: string) => {
       const conn = storeRef.current.connections.get(contextKey)
-      if (!conn) return
+      if (!conn) {
+        // connect() is still in flight — mark as abandoned so it
+        // tears down immediately when acpConnect returns.
+        if (connectingKeysRef.current.has(contextKey)) {
+          abandonedKeysRef.current.add(contextKey)
+        }
+        return
+      }
       await acpDisconnect(conn.connectionId)
       reverseMapRef.current.delete(conn.connectionId)
       lastActivityRef.current.delete(contextKey)
diff --git a/src/hooks/use-connection-lifecycle.ts b/src/hooks/use-connection-lifecycle.ts
index b18e924..6dfe0ae 100644
--- a/src/hooks/use-connection-lifecycle.ts
+++ b/src/hooks/use-connection-lifecycle.ts
@@ -55,6 +55,7 @@ export function useConnectionLifecycle({
     status,
     selectorsReady,
     connect: connConnect,
+    disconnect: connDisconnect,
     sendPrompt,
     setMode: connSetMode,
     setConfigOption: connSetConfigOption,
@@ -256,9 +257,18 @@ export function useConnectionLifecycle({
     t,
   ])
 
-  // Clean up lingering task on unmount (e.g. tab closed while connecting)
+  // Keep a ref to disconnect so the unmount cleanup always calls the
+  // latest version without adding it as a dependency.
+  const connDisconnectRef = useRef(connDisconnect)
+  useEffect(() => {
+    connDisconnectRef.current = connDisconnect
+  }, [connDisconnect])
+
+  // Clean up on unmount (e.g. tab closed): disconnect the ACP connection
+  // so it doesn't leak, and remove lingering tasks.
   useEffect(() => {
     return () => {
+      connDisconnectRef.current().catch(() => {})
       if (taskIdRef.current) {
         removeTask(taskIdRef.current)
       }