Windows 10: Codex background process causes intermittent system-wide mouse stutter

Summary

After a recent Windows 10 update, launching Codex causes intermittent mouse-input stutter across the whole system.

The stutter continues even after closing the Codex window. It stops immediately only after fully terminating the Codex process tree. Launching Codex again makes the issue return.

This appears to be related to Codex remaining active in the background and periodically attempting to collect process snapshots through WMI.

Environment

• OS: Windows 10 Pro, version 10.0.19045.6466
• Codex Desktop version: 26.715.4045.0
• Codex executable: C:\Program Files\WindowsApps\OpenAI.Codex_26.715.4045.0_x64__2p2nqsd0c76g0\app\resources\codex.exe

Steps to reproduce

1. Restart Windows.
2. Launch Codex Desktop.
3. Use the PC normally for a while.
4. Intermittent system-wide mouse stutters begin occurring.
5. Close the Codex window.
6. The stutters continue.
7. Run:

taskkill /F /IM codex.exe /T

1. The stutters stop immediately.
2. Launch Codex again.
3. The stutters return.

Expected behavior

Closing Codex should fully stop any background activity that can affect system responsiveness. Codex should not cause periodic system-wide mouse-input stutter.

Actual behavior

• Closing the Codex window does not terminate codex.exe and its child processes.
• The system intermittently stutters until the full Codex process tree is terminated.
• The issue is reproducible: killing the process resolves it, while relaunching Codex brings it back.

Relevant logs

The Codex log repeatedly contains this warning at roughly 16 minute 30 second intervals:

[electron-sampler] Failed to collect child process snapshot

The sampler invokes PowerShell/WMI queries including:

Get-CimInstance Win32_PerfFormattedData_PerfProc_Process
Get-CimInstance Win32_Process

At the same time, Windows Event Viewer contains repeated WMI Activity errors involving:

Win32_PerfFormattedData_PerfProc_Process
ResultCode: 0x800706BA
Could not send status to client

The ResizeObserver loop completed with undelivered notifications messages also appear in the log, but they seem unrelated to the system-wide input stutter.

Notes

• There are no obvious Codex crash reports, GPU reset events, or sustained high CPU usage when checking after the stutter.
• The direct WMI query succeeds but takes roughly 700 ms on this machine.
• This may be related to the Electron process sampler and its repeated WMI process enumeration after recent Windows updates.