[Windows][26.810.7004.0] Mouse movement over Codex window causes MAIN/renderer CPU spikes; WMI/Defender also become active

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

26.810.7004.0

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?

On Codex Desktop for Windows 26.810.7004.0, mouse movement over the Codex window causes large and reproducible CPU spikes in the Electron MAIN and renderer processes, even when no agent task is running.

When the Codex window is left untouched, CPU usage falls close to idle. Simply moving the mouse repeatedly over the Codex window causes the MAIN and renderer processes to become busy again. The Codex window does not need to be focused or brought to the foreground for this to reproduce.

Example 10-second CPU sample while the window is left untouched:

_ChatGPT renderer: ~5.2% of one logical core
ChatGPT process: ~4.2%
ChatGPT MAIN: ~2.0%
plugin-appserver: ~0%_

After leaving the application untouched for longer, most Codex processes can fall close to 0%.
If I move the mouse repeatedly over the Codex window without clicking:

_ChatGPT MAIN: ~38.1% of one logical core
ChatGPT renderer: ~38.0%
ChatGPT gpu-process: ~12.7%
plugin-appserver: ~0%_

The relevant Chromium/Electron process types were identified from their command lines:

_PID 8092 MAIN
PID 24476 gpu-process
PID 19060 renderer
PID 1692 renderer
PID 26056 renderer_

PIDs change after restarting Codex.
Opening an existing conversation also causes a reproducible CPU spike. One example:

_ChatGPT renderer: ~33.4% of one logical core
ChatGPT MAIN/other UI: ~27.5%
another ChatGPT process: ~17.8%
plugin-appserver codex: ~15.8%_

After leaving the window untouched, CPU usage falls again.

I also observe WMI Provider Host and Microsoft Defender becoming some of the higher CPU consumers when Codex starts or becomes active.
This behavior appeared/reappeared after a Codex Desktop update.

What steps can reproduce the bug?

1. Launch Codex Desktop on Windows.
2. Do not start an agent task.
3. Leave the Codex window untouched for a while.
4. Observe that CPU usage eventually falls close to idle.
5. Move the mouse repeatedly over the Codex window without clicking.
6. Observe that the Codex MAIN and renderer processes immediately consume substantial CPU.
7. Stop moving the mouse.
8. Observe that CPU usage falls again.
9. Open an existing conversation.
10. Observe another CPU spike involving multiple ChatGPT.exe processes and sometimes the plugin app-server.

The mouse-movement reproduction does not require the Codex window to be focused.
I can reproduce this with plugins = false.
No user MCP servers are configured, and standalone user/project skills were removed during troubleshooting.

What is the expected behavior?

When no agent task is running, Codex Desktop should remain close to idle.
Mouse movement or hover over an otherwise idle Codex window should not consume a significant fraction of one or more CPU cores.
Opening or switching conversations may briefly use CPU, but CPU usage should fall quickly after the UI finishes updating.
WMI Provider Host and Microsoft Defender should also not remain unusually active simply because Codex Desktop is open.

Additional information

Hardware
CPU:
AMD Ryzen 7 5800H with Radeon Graphics
8 physical cores / 16 logical processors

Discrete GPU:
NVIDIA GeForce RTX 3060 Laptop GPU

Display / virtual display devices:
AMD integrated Radeon Graphics
NVIDIA GeForce RTX 3060 Laptop GPU
OrayIddDriver Device

Internal display refresh rate is fixed at 165 Hz.

I also tested an external display at 60 Hz. Changing the external display to 60 Hz did not resolve the problem.

GPU utilization is generally low during reproduction. Moving the mouse over the Codex window can increase DWM/GPU activity slightly, but the dominant increase is CPU usage in Codex's MAIN and renderer processes.

Codex / ChatGPT versions
OpenAI.Codex:
26.810.7004.0

Package:
OpenAI.Codex_26.810.7004.0_x64__2p2nqsd0c76g0

ChatGPT Desktop / Classic package also installed:
OpenAI.ChatGPT-Desktop 1.2026.190.0
Troubleshooting already performed
Tested plugins = false.
No configured user MCP servers.
Removed standalone project/user skills.
Rebuilt ~/.codex/.tmp.
Rebuilding .tmp reduced some baseline CPU usage but did not fix the mouse-movement CPU spike.
Tested an external display at 60 Hz with no meaningful improvement.
GPU utilization remains relatively low during the issue.
Leaving the Codex window untouched allows CPU usage to fall substantially.
Moving the mouse over the Codex window reliably wakes the MAIN and renderer processes.
The VS Code Codex extension does not show the same sustained CPU behavior.
Fully quitting Codex removes the Codex Desktop CPU usage.

Earlier I also observed a separate high-CPU condition involving:
~/.codex/plugins/.plugin-appserver/codex.exe

Setting:

[features]
plugins = false

significantly reduced that particular plugin-appserver CPU issue, but it does not prevent the current MAIN/renderer mouse-movement issue after the latest Codex Desktop update.

There also appears to be related WMI Provider Host / Microsoft Defender activity when Codex starts or becomes active.