[BUG] Remote Control: exiting one process ends the session another process just re-attached (2.1.288)

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Two Claude Code processes run on the same machine under the same account. Process B re-attaches process A's session (claude --resume <A's session id>, then /remote-control), and B takes over the Remote Control bridge session. When A then exits gracefully with /exit, A's exit ends the session B now holds.

B's debug log shows, in order:

1. an inbound end_session control request;
2. Epoch mismatch (409, reason=session_not_active);
3. "this session was ended or archived from another device or app (code 4090)".

The 2.1.288 changelog lists a fix for this case; it still reproduces.

What Should Happen?

A's exit cleans up only what A still owns. The session B now holds stays connected.

Error Messages/Logs

end_session (inbound control request)
Epoch mismatch (409, reason=session_not_active)
this session was ended or archived from another device or app (code 4090)

Steps to Reproduce

1. Start process A with Remote Control on and run one turn.
2. Start process B on the same machine: claude --resume <A's session id> --debug. At startup B declines to enable Remote Control because A holds it.
3. In B, run /remote-control. B takes over the Remote Control bridge session.
4. About six seconds later, exit A gracefully with /exit.
5. B's session ends; B's debug log shows the three lines under Error Messages/Logs, in that order.

Claude Model

None

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.288 (Claude Code), where this was reproduced. 2.1.289 is installed now; its changelog lists no Remote Control change.

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

• macOS 27 (Apple Silicon); both processes on the same machine and account.
• The 2.1.288 changelog lists a fix for this case; it still reproduces there.
• Secondary: when reached from another machine, the session answered to its auto-generated Remote Control title, not the local session name.