[macOS][26.820.60940] Streaming replies are obscured by the composer until switching conversations

What version of the Codex App are you using (From “About Codex” dialog)?

26.820.60940 (bundle build 7119)

What subscription do you have?

Not provided; the account plan was not inspected for this report.

What platform is your computer?

Darwin 24.5.0 arm64 arm

macOS 15.5 (build 24F74), Apple Silicon.

What issue are you seeing?

After updating the Codex desktop app to 26.820.60940, streamed assistant messages can extend underneath the fixed composer/input box at the bottom of the conversation. The newest lines are therefore clipped or completely hidden, so the response appears incomplete.

The transcript does not appear to reserve enough bottom space or recompute its scroll/layout position as streaming content is appended. Once the view enters this state, the only reliable workaround observed is to switch to another conversation and then reopen the affected conversation. Re-entering the conversation causes the layout to refresh and the hidden content becomes visible.

This is a desktop layout/rendering regression, not a model-output problem.

What steps can reproduce the bug?

1. Update the Codex desktop app to version 26.820.60940.
2. Open an existing conversation.
3. Send a prompt that produces a multi-paragraph streamed response.
4. Keep the conversation near the bottom while the response is streaming.
5. Observe that newly appended lines and the message action row can end up behind the fixed composer/input box.
6. Switch to another conversation, then reopen the affected conversation.
7. Observe that the transcript layout is recalculated and the previously hidden content becomes visible.

The issue has reproduced repeatedly since the update. The exact trigger may depend on response length and layout height.

What is the expected behavior?

While the user is at or near the bottom of the conversation, streamed content should remain fully visible above the composer. The transcript should reserve bottom inset/padding equal to the composer height and keep the scroll position updated as new lines are appended. Switching conversations should not be required to reveal the end of a response.

Additional information

• Regression first observed immediately after the 26.820.60940 update on August 26, 2026.
• Only known workaround: switch to another conversation and reopen the affected one.
• A screenshot was captured, but it contains private conversation content and is intentionally not attached to this public issue. It clearly shows the response text/action row intersecting the top edge of the composer.
• Related but not identical reports: #31711 and #38113. This report adds a current-version macOS reproduction specifically during streaming, with thread switching as the only observed recovery.