[Bug] Windows Codex Desktop sidebar flickers / renders incorrectly with GPU acceleration enabled #24904

What issue are you seeing?

Summary

Codex Desktop on Windows has a GPU/hardware-accelerated rendering issue. The left sidebar flickers during assistant thinking/streaming, and in light mode the sidebar becomes extremely dark/low-contrast with white hover rectangles. Launching Codex with GPU disabled / software rendering makes the UI render normally, which strongly suggests the issue is specific to the GPU compositing path.

Environment

• OS: Windows
• Codex Desktop package: OpenAI.Codex_26.519.11010.0_x64
• App release seen in logs: 26.519.81530
• Electron seen in logs: 42.1.0
• Workspace: C:\Users\31236\Documents\DZH
• Display scale: 125% observed in renderer args (--device-scale-factor=1.25)

Reproduction

1. Start Codex Desktop normally on Windows.
2. Use light mode.
3. Observe the left sidebar.
4. Hover sidebar items.
5. Send a prompt and wait while the assistant is thinking/streaming.
6. Switch to dark mode and repeat.
7. Launch Codex with GPU disabled / software rendering and compare.

Actual Behavior

• In light mode, the left sidebar renders almost black / very low contrast.
• Hovering items in the left sidebar shows white rectangular artifacts.
• In dark mode the sidebar is readable, but the left side still flickers during assistant thinking/streaming.
• Normal launch shows a GPU process in command line:
  --type=gpu-process
• At least one log contained:
  Recoverable Chromium child process gone ... processType=GPU reason=killed serviceName=GPU

Expected Behavior

The sidebar should render consistently in light and dark mode, with no flickering or hover artifacts during assistant activity.

Important Finding

When launching Codex with GPU disabled / software rendering, the UI renders normally and the sidebar flicker disappears. This strongly suggests a Windows GPU / hardware acceleration / Chromium compositing issue rather than a project configuration issue.

Things Already Tried

• Switched between light and dark mode.
• Cleared Codex GPU/cache state.
• Installed Git for Windows and fixed PATH.
• Initialized the workspace as a Git repo.
• Fixed safe.directory / dubious ownership warnings.
• Cleared Codex Local Storage / stale feature-flag cache.
• Restarted Codex multiple times.

These reduced unrelated log noise, but the sidebar rendering/flicker issue persisted under normal GPU-accelerated launch.

Related Public Reports

There appear to be other Windows Codex Desktop UI/GPU/flicker/freeze reports, including:

• codex apps windows Blank #19352
• Codex Windows app stuck on blank/spinner at startup — unsupported workspace_dependencies feature loop #19437
• Codex App freezes / becomes Not Responding when opening image-heavy projects with many generated images #21232

This report adds the key observation that disabling GPU/software rendering makes the UI normal.

What steps can reproduce the bug?

1. On Windows, launch Codex Desktop normally.
2. Use light mode.
3. Observe the left sidebar: it appears very dark / low contrast.
4. Move the mouse over items in the left sidebar.
5. Observe white rectangular hover artifacts.
6. Send any prompt and wait while the assistant is thinking or streaming a response.
7. Observe that the left sidebar flickers during assistant activity.
8. Switch to dark mode.
9. The sidebar becomes readable, but flickering still occurs during assistant thinking/streaming.
10. Launch Codex with GPU disabled / software rendering.
11. Observe that the sidebar renders normally and flickering disappears.

What is the expected behavior?

The left sidebar should render correctly in both light and dark mode, without dark/white hover artifacts, and it should not flicker while the assistant is thinking or streaming a response.

GPU-accelerated normal launch and software-rendered launch should have consistent UI rendering behavior.

Additional information

Hi, I’m seeing a Codex Desktop Windows GPU rendering bug.

In normal launch, the left sidebar flickers during assistant thinking/streaming. In light mode the sidebar becomes almost black/low contrast and hover states show white rectangular artifacts. In dark mode it is readable but still flickers.

Launching Codex with GPU disabled/software rendering makes the UI normal, so this appears to be a Windows GPU / Chromium compositing issue.

Environment:

• Windows
• Codex Desktop: OpenAI.Codex_26.519.11010.0_x64
• Release in logs: 26.519.81530
• Electron in logs: 42.1.0
• Display scale: 125%

I already tried clearing cache/Local Storage, installing Git, fixing PATH and Git safe.directory warnings, and restarting. The issue persists only under normal GPU-accelerated launch.