Windows: Inconsistent auto-scrolling / viewport positioning in regular chats

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

26.908.40824

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Windows x64

What issue are you seeing?

The conversation viewport does not scroll consistently when a new assistant response is generated in a regular ChatGPT chat.

Within the same chat and without changing the window size, I have observed several different behaviors:

• sometimes the conversation scrolls normally and the new response is positioned correctly;
• sometimes it scrolls only partially, leaving a large unused blank area below the newest response;
• sometimes it does not scroll to the new response at all, so the new response begins at or below the bottom edge of the visible viewport.

The issue appears to occur particularly after sending messages containing text, although I have not confirmed the exact trigger. In one test, a message containing only an image behaved normally.

This behavior does not occur in:

• the ChatGPT web app;
• the ChatGPT Classic Windows app.

This issue has been present for several app versions, since the redesigned Windows app replaced ChatGPT Classic.

Possibly related: #37884 reports abnormal scrolling and large blank areas in the redesigned app on macOS. This report confirms similar behavior on Windows and additionally includes cases where the new response is not scrolled into view at all.

What steps can reproduce the bug?

1. Open an existing regular ChatGPT conversation in the redesigned Windows app.
2. Send a text message.
3. Wait for the assistant response to start or finish generating.
4. Observe the viewport position.

What is the expected behavior?

When a new assistant response is generated, the conversation should consistently keep the new response in view and make normal use of the available vertical viewport, matching the behavior of the web app and ChatGPT Classic.

Additional information

I have screenshots showing three states in the same conversation:

• normal scrolling;
• partial scrolling with a large blank area below the newest response;
• no automatic scroll to the new response.

No source file or test is identified in the report. Start by reproducing the viewport behavior in the Windows x64 app with a regular chat and text message, then compare the normal, partially scrolled, and unscrolled states with the expected web or Classic app behavior. Done means new assistant responses remain consistently visible without a large unused blank area.