codex - 💡(How to fix) Fix Codex Desktop conversation output vertically jitters while reading results

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

Version 26.513.31313 (2867)

Bundled Codex CLI from the running app bundle: codex-cli 0.131.0-alpha.9 Global codex --version: codex-cli 0.125.0

What subscription do you have?

Not included here. This appears to be a local Desktop UI/rendering issue rather than a plan-specific behavior.

What platform is your computer?

Darwin 24.6.0 arm64 arm

Additional environment:

• macOS 15.6.1 (24G90)
• MacBook Pro Mac16,1, Apple M4, 16 GB memory
• Electron observed from Codex process metadata: 42.0.1
• Displays connected:
  • Built-in Liquid Retina XDR display, 3024 x 1964 Retina
  • DELL SE2723DS external display, 2560 x 1440 @ 75 Hz
• App language / locale observed locally: zh-Hans-CN

What issue are you seeing?

The Codex Desktop conversation/result pane can show persistent small vertical jitter while viewing assistant results. The output appears to move up and down by a few pixels repeatedly, as if the conversation area is continuously reflowing/repainting. It is not a one-time large jump; it is a subtle but continuous visual wobble that makes the rendered answer feel like it is twisting on screen.

This is a severe Desktop UX problem. The core job of Codex Desktop is to let users read, inspect, and reason about generated answers, tool output, diffs, and code changes. When the result pane is visually unstable, even by a small amount, it becomes uncomfortable and distracting to read long answers. This materially degrades the usability of the app and should be treated as a high-priority rendering/readability bug by the Desktop UI team.

What steps can reproduce the bug?

1. Open Codex Desktop on macOS.
2. Open an existing conversation or run a prompt that produces a multi-paragraph assistant result / tool-heavy response.
3. Keep the main conversation result pane visible and try to read the generated output.
4. Observe the result area: the visible content can repeatedly shift slightly up/down, producing a continuous micro-jitter / wobble.

The issue is most noticeable because the movement is small but repeated. It is visually different from normal streaming text updates, normal scroll inertia, or a deliberate scroll position change.

What is the expected behavior?

The conversation/result pane should remain visually stable while a user is reading. Streaming, layout refreshes, side panels, sidebar state, or background updates should not cause the already-visible output to oscillate vertically.

What is the actual behavior?

The visible result content can jitter vertically by a small amount over and over. The text/output appears to shake or twist while reading, making the app feel unstable and causing eye strain during longer responses.

Related issues checked

I searched existing openai/codex issues before filing this. There are related Desktop rendering/scrolling reports, but they do not fully cover this exact symptom:

• #11901: broad UI flickering while Codex is working
• #22860: generated text flickers while a response is in progress
• #22333: UI twitches/reflows on screen refresh when the sidebar is open
• #17169: chat scroll jumps/bounces when scrolling in long conversations
• #20788 / #20850: flicker/shake when switching threads or sessions

This report is specifically about persistent small vertical jitter of the conversation output while reading results, not only thread switching, a single refresh twitch, or a large scroll-position jump.

Additional information

No screen recording is attached yet, but the issue is visible during normal reading and has a high impact on the perceived quality and readability of Codex Desktop. Please prioritize this because a stable reading surface is a baseline requirement for a coding assistant UI.