[BUG] [macOS] Cowork responses generated but not rendered until UI is manually triggered

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report
• [x] I am using the latest version of Claude Code

What's Wrong?

Claude Desktop Cowork on macOS generates responses successfully, but they do not appear in the UI until manually triggered. The response exists (confirmed by the fact it appears instantly when triggered) but the frontend fails to re-render to display it.

Two workarounds force the response to appear:

1. Type anything in the input field and send — the hidden response then appears, and the reply to the new input is itself hidden (perpetuating the cycle)
2. Switch to a different task/chat thread and switch back — the missing response then appears

This suggests the chat view is not receiving or acting on a re-render trigger when the response stream completes.

Possibly Related Issues

• #18974 — Cowork hangs on "Sending request..." due to conversation_uuid validation error (same class: backend works, frontend doesn't update)
• #25177 — Cowork unresponsive, VM boots but UI shows nothing

Note

This appears to be the same root cause as #18974 (opened January 18, 2026), still present over a month later in the latest build.

Environment

• macOS (Apple Silicon, Mac mini)
• Claude Desktop: 1.1.3541 (1e65e4), build date 2026-02-18
• Cowork mode only — standard Chat works fine

Steps to Reproduce

1. Open Claude Desktop on macOS
2. Switch to Cowork tab
3. Start or continue a task
4. Send a message
5. Observe: response is generated (spinner stops / activity completes) but no text appears
6. Type any follow-up message OR switch to another task thread and back
7. Observe: the previously hidden response now appears

Expected Behavior

Responses should render in the UI immediately upon generation.

Logs

Log evidence shows the same REACT_QUERY_CLIENT UUID validation failure as #18974, preceded by ~95 unknown sdk message type: queue-operation warnings.

From ~/Library/Logs/Claude/claude.ai-web.log:

2026-02-19 13:19:13 [warn] [LOCAL_SESSION] unknown sdk message type: queue-operation
2026-02-19 13:19:13 [warn] [LOCAL_SESSION] unknown sdk message type: queue-operation
... (repeated ~95 times before the error)
2026-02-19 13:19:41 [error] [REACT_QUERY_CLIENT] QueryClient error: Error: path.conversation_uuid: Input should be a valid UUID, invalid character: expected an optional prefix of `urn:uuid:` followed by [0-9a-fA-F-], found `l` at 1