[BUG] Desktop app (Code tab): unsent draft is lost when switching sessions (CLI unaffected)

What's wrong?

In the Claude desktop app (Code tab), the text I've typed or edited in the message box is lost when I switch to another session. I type a message, revise it without sending, and switch to a different session. When I come back, the revised text is gone.

This happens only in the desktop app. In the terminal CLI, the same workflow keeps the text. It reproduces every time; it is not intermittent.

Steps to reproduce

1. Open the Claude desktop app, Code tab, with more than one session.
2. In session A, type a message in the message box. Do not send it.
3. Edit that text (delete or rewrite part of it). Still do not send it.
4. Switch to session B in the sidebar.
5. Switch back to session A.

Expected: the message box still holds the edited, unsent text.
Actual: the edited text is gone.

Related issues

The same class of bug has been reported on other surfaces, all mobile or Remote Control: #65224 (iOS, closed as duplicate), #96700 (mobile Code tab, open), #65425 (Remote Control). This report is for the macOS desktop app, which none of them cover.

Environment

• Claude desktop app: 2.9939.2
• Claude Code CLI (not affected): 2.1.283
• macOS 26.3.2 (Apple Silicon)