A serve that lost the port race had already signed in, so client.json named a port another engine held and every client talked to that one. The socket is now bound first and handed to uvicorn. Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01QgG6TJw5qBZzaLghQSRVrq