[Windows][ChatGPT Desktop] Missing scroll-to-bottom control and viewport jumps leave large blank area

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

ChatGPT desktop app 26.825.32147 (released August 28, 2026)

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

The Windows desktop app currently shows two related navigation/scroll regressions that significantly affect usability in long conversations.
First, the floating scroll-to-bottom control/arrow is consistently absent in the Windows desktop app. This is not limited to a specific conversation or to moments when a scroll glitch occurs; the control appears to be missing in normal long-chat use as well.
Second, after sending a message, the conversation viewport can jump to an incorrect position. In the reproduced case, the newly generated assistant response remained near the top of the visible area while a very large blank area appeared between the response and the message composer at the bottom of the window.
These two behaviors compound each other. When the viewport jumps away from the most recent response, the missing scroll-to-bottom control removes the quickest way to return to the latest content. I am forced to navigate using the narrow vertical scrollbar at the side of the window, which slows down normal interaction and makes it easier to lose the current reading position or accidentally close the app window while trying to navigate.
I have not observed conversation data loss. The issue is with viewport/navigation behavior and recovery within the Windows desktop interface.
Feedback was already submitted from the affected Windows desktop session through Help → Comments with session logs included.
Feedback ID: no-active-thread-01a04bed-c5ca-7402-94b6-1a3953a1a5bb

What steps can reproduce the bug?

1. Open a long existing conversation in the ChatGPT Windows desktop app.
2. Scroll within the conversation and observe that the floating scroll-to-bottom control/arrow is not available.
3. Continue the conversation by sending a new message.
4. Wait for the assistant response to finish generating.
5. Observe that the viewport can jump to an incorrect position rather than remaining near the latest generated content.
6. In the reproduced case, the assistant response remained near the top of the visible area while a large blank area appeared between the response and the composer.
7. Attempt to return to the latest content.
8. Because the scroll-to-bottom control is absent, navigation must be done manually using the narrow vertical scrollbar.
   The missing scroll-to-bottom control is persistent and can be observed independently of the viewport-jump/blank-area behavior.
   Visual evidence 1 — Windows desktop: reproduced viewport-jump state showing the large blank area between conversation content and the composer.

Visual evidence 2 — Reference from chatgpt.com in Microsoft Edge: the scroll-to-bottom arrow referred to in this report is visible above the composer.

What is the expected behavior?

The Windows desktop app should keep the user near the newly generated response during normal conversation flow.
If the user is not at the bottom of the conversation, a visible scroll-to-bottom control should be available to quickly return to the latest content.
The viewport should not jump past the response or create a large blank area between the latest conversation content and the message composer.

Additional information

This issue is reproducible in the ChatGPT Windows desktop app version 26.825.32147.
The missing scroll-to-bottom control appears to be persistent in long conversations, while the viewport-jump/blank-area behavior occurs intermittently after sending messages.
The practical impact is significant in long conversations because recovering the latest response requires manual scrolling through a narrow scrollbar instead of using the expected quick-navigation control.
I have observed no conversation data loss.
Potentially related issues suggested by GitHub:

• #36798 — previously rendered text vertically jitters while responses are streaming.
• #32016 — text flickering and overlapping when scrolling through long ChatGPT conversations.
• #18109 — scroll bar error.
  These appear related to scrolling/rendering behavior, but they do not describe the same combination observed here: a persistently missing scroll-to-bottom control together with the reproduced viewport jump/large blank-area state.
  Feedback ID: no-active-thread-01a04bed-c5ca-7402-94b6-1a3953a1a5bb
  The Windows app reports that it is up to date as of August 28, 2026.

No implementation files or tests are named. Start by reproducing the issue in a long existing conversation on the Windows desktop app version 26.825.32147, following the listed send-and-scroll steps. Done means the viewport stays near the generated response, no large blank area appears, and a scroll-to-bottom control is available when the user is away from the latest content.