[Windows 11][26.813.12317] ChatGPT/Codex causes persistent system-wide mouse lag and ~10% CPU while idle

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

chatgpt 26.813.12317

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?

After updating the Windows ChatGPT/Codex app to version 26.813.12317, the app intermittently enters a state that causes severe system-wide mouse/touchpad lag.

When the issue occurs:

• ChatGPT.exe continuously consumes approximately 9.5–10% CPU while completely idle.
• No Work or Codex task is running.
• Mouse/touchpad movement becomes severely choppy in the Windows desktop, Chrome, and other normal applications.
• Mouse movement remains completely smooth inside Task Manager and on the Ctrl+Alt+Delete secure desktop.
• Minimizing ChatGPT does not help.
• Switching to a new empty chat does not help.
• Restarting dwm.exe does not help.
• Resetting the graphics driver with Win+Ctrl+Shift+B does not help.
• Completely terminating ChatGPT immediately restores normal mouse/touchpad movement.
• Reopening ChatGPT temporarily resolves the issue, but it returns after the app has been running for some time.

This issue started on the same day that the Windows ChatGPT client updated. I had not experienced this problem previously.

Process Explorer investigation

During the issue, Microsoft Process Explorer showed one ChatGPT.exe process consuming approximately 9.6% CPU, with most other ChatGPT/Codex processes near idle.

CPU activity was concentrated in several threads. The highest-CPU thread was consuming approximately 4.5% CPU.

Its call stack contained sustained Chromium/V8 activity, including:

• chrome.dll!v8::ExternalMemoryAccounter
• chrome.dll!v8::ScriptCompiler::CreateCodeCache
• chrome.dll!v8::Object
• chrome.dll!v8::ValueSerializer
• chrome.dll!ChromeMain

As an additional diagnostic test, I temporarily suspended the highest-CPU thread. This caused mouse responsiveness to become dramatically worse (almost unusable). Resuming the thread immediately returned the system to the original choppy state. I did not suspend any additional threads.

Overall system CPU, GPU, and disk utilization remain relatively low during the issue, so this does not appear to be normal resource exhaustion.

What steps can reproduce the bug?

1. Launch ChatGPT/Codex for Windows version 26.813.12317.
2. Use the application normally or leave it running for some time.
3. Eventually, mouse/touchpad movement becomes severely choppy across normal Windows applications.
4. Open Task Manager and observe that mouse movement inside Task Manager remains smooth.
5. Open the Ctrl+Alt+Delete secure desktop and observe that mouse movement remains smooth there as well.
6. Return to the normal desktop and the lag is immediately noticeable again.
7. Observe ChatGPT.exe consuming approximately 9.5–10% CPU, even with no active Work/Codex task.
8. Completely terminate ChatGPT.
9. Mouse/touchpad movement immediately returns to normal.
10. Restart ChatGPT. The system remains normal temporarily, but the issue eventually returns.

The issue has reproduced multiple times, including after a full Windows restart.

What is the expected behavior?

Additional information

No response

The report names no source file or test. Reproduce on Windows with ChatGPT/Codex 26.813.12317, then inspect the ChatGPT.exe process and the reported Chromium/V8 call stacks while the app is idle. Done means the app no longer causes persistent mouse lag or roughly 10% idle CPU.