diff --git a/components/frontend/src/app/projects/[name]/sessions/[sessionName]/page.tsx b/components/frontend/src/app/projects/[name]/sessions/[sessionName]/page.tsx
index 169ec1697..80e467a79 100644
--- a/components/frontend/src/app/projects/[name]/sessions/[sessionName]/page.tsx
+++ b/components/frontend/src/app/projects/[name]/sessions/[sessionName]/page.tsx
@@ -219,9 +219,11 @@ export default function ProjectSessionDetailPage({
   const aguiState = aguiStream.state;
   const aguiSendMessage = aguiStream.sendMessage;
   const aguiInterrupt = aguiStream.interrupt;
-  const isRunActive = aguiStream.isRunActive;
+  // Fix #404: Force isRunActive to false when session is in terminal state (Failed, Completed, Stopped)
+  const rawIsRunActive = aguiStream.isRunActive;
+  const isRunActive = rawIsRunActive && !["Failed", "Completed", "Stopped"].includes(phase);
   const aguiConnectRef = useRef(aguiStream.connect);
-  
+
   // Keep connect ref up to date
   useEffect(() => {
     aguiConnectRef.current = aguiStream.connect;
diff --git a/components/frontend/src/components/session/MessagesTab.tsx b/components/frontend/src/components/session/MessagesTab.tsx
index f717d580c..9513f4e4e 100644
--- a/components/frontend/src/components/session/MessagesTab.tsx
+++ b/components/frontend/src/components/session/MessagesTab.tsx
@@ -351,8 +351,8 @@ const MessagesTab: React.FC<MessagesTabProps> = ({ session, streamMessages, chat
           </div>
         )}
 
-        {/* Show loading indicator when agent is actively processing */}
-        {shouldShowMessages && isRunActive && filteredMessages.length > 0 && (
+        {/* Show loading indicator when agent is actively processing (Fix #403) */}
+        {shouldShowMessages && isRunActive && (
           <div className="pl-12 pr-4 py-2">
             <LoadingDots />
           </div>