Session list shows a session as "completed" (or later, "busy") but it can't be reopened either way

Environment: Claude Code 2.1.243, CentOS Stream 9, tmux-backed session

Steps to reproduce / actual sequence observed:

1. Have an active session running (in my case, backed by a tmux pane), actively in use.
2. Without me exiting or ending it, the session list suddenly shows it as completed.
3. Attempting to reopen it from that "completed" state fails -- can't get back into it.
4. Exit Claude Code entirely (/exit) and restart.
5. Resume into that same session (claude --resume) and start working / send it a prompt -- this part succeeds, the session responds.
6. Switch to the session list page again.
7. The list now shows the session as busy/working (consistent with step 5's activity) -- but clicking into it still doesn't open it.

Expected: The session list accurately reflects the session's real state, and a session shown as active (whether "completed" was ever accurate or not) can always be reopened from the list.

Actual: The list's displayed state doesn't match reality (shown completed while still in use), and regardless of which state it displays -- completed or busy -- clicking the session does not reopen it.

Additional context: The underlying session itself was never dead -- a separate concurrent session confirmed via its own tooling that this session was alive, actively processing, and backed by a live tmux pane throughout. This points to a UI/session-list-state bug, not a crashed session. I was consistently working from the same tmux pane the whole time, ruling out a wrong-terminal cause