[macOS][ChatGPT Desktop] Message composer disappears when scrolling up after a response

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

26.901.31953

What subscription do you have?

Unknown

What platform is your computer?

Darwin 25.6.0 arm64 arm

What issue are you seeing?

In the ChatGPT desktop app on macOS, after the model finishes generating a response, scrolling upward to read earlier messages causes the message composer/input box at the bottom of the conversation to disappear.

This interrupts the conversation flow because the user can no longer see the input area while reviewing prior context.

What steps can reproduce the bug?

1. Open the ChatGPT desktop app on macOS.
2. Open a Chat conversation with enough history to scroll.
3. Send a message and wait for the model to finish its response.
4. Scroll upward to read earlier messages.
5. Observe that the message composer/input box disappears from the bottom of the window.

What is the expected behavior?

The message composer should remain visible and anchored at the bottom of the window while the conversation history scrolls independently. Scrolling up to read earlier messages should not remove the input area.

Additional information

Observed on 2026-09-04.

Related reports:

• #38220 — viewport/composer layout issue while reading scrolled history
• #42649 — composer disappears or moves off-screen on Windows while Work is running

This report is distinct because it occurs on macOS in Chat mode after the response has finished. No screenshot is attached because the reproduced conversation contains private content.

First reproduce the issue in the macOS ChatGPT desktop app using a conversation with enough history, then trace the Chat-mode message composer and conversation scrolling behavior. Done means the composer remains visible and anchored at the bottom while earlier messages are scrolled, including after a response finishes.