Showing the panel connects a frame later (the panel needs its width first). A shell that ended before that frame -- reopened and closed by the server within one frame, as headless CI's slow frames made happen -- was quietly replaced by a new one, against "no reconnect of its own". The frame now connects only if no shell was open as the showing began. The cause of the B3 failures on GitHub since 94e903e; a test makes it happen every time. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>