Computer History causes severe performance degradation in a Qt application on macOS

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

26.908.70816

What subscription do you have?

Chat GPT Pro 5x

What platform is your computer?

macOS Darwin 27.2.0 arm64 arm

What issue are you seeing?

I found a reproducible interaction between the Codex desktop Computer History feature and Tibia on macOS.

Environment

• MacBook Pro 14-inch, Apple M4 Pro
• 48 GB unified memory
• macOS 27.0
• Tibia macOS client
• Tibia uses Qt / Qt Quick and currently runs as an x86-64 process through Rosetta

Reproduction

1. Launch Tibia.
2. Performance is normal at approximately 190–200 FPS.
3. Enable/use Codex Computer History while Tibia is not excluded.
4. Interact with Tibia's UI for a short period.
5. FPS progressively decreases, sometimes reaching approximately 30 FPS.
6. Disable Computer History or close Codex.
7. Tibia immediately returns to normal FPS without restarting.
8. Re-enable Computer History and the issue returns.

Important isolation test

If Tibia is added as an exception/excluded application in Computer History, the problem does not occur.

Computer History can remain enabled for other applications and Tibia continues running normally.

This strongly indicates that the issue occurs specifically while Computer History is inspecting/processing the Tibia window.

macOS sampling results

During the affected state, Tibia's main thread spends a very large amount of time servicing macOS Accessibility requests through Qt.

Representative stack:

_XCopyMultipleAttributeValues
_AXXMIGCopyMultipleAttributeValues
NSAccessibilityChildren
QAccessibleQuickWindow::child()
QtQuick

In one affected sample, approximately 1,114 out of 1,754 main-thread samples were inside a single Accessibility request path, with approximately 1,105 samples involving:

QAccessibleQuickWindow::child()

Other frequently observed Qt Quick paths included:

QQuickDeliveryAgentPrivate::deliverHoverEventRecursive()
QQuickItemPrivate::itemToWindowTransform()
QQuickWindowPrivate::findCursorItemAndHandler()

Some UI components, particularly Tibia's Action Bars, make the problem much easier to reproduce because they appear to create a larger/more dynamic Qt Quick tree.

Expected behavior

Computer History should inspect an application without causing substantial performance degradation in the inspected process.

Actual behavior

When Tibia is included in Computer History monitoring, Accessibility/UI inspection can consume most of Tibia's main thread and reduce its frame rate from approximately 200 FPS to approximately 30 FPS.

Excluding Tibia from Computer History completely prevents the issue.

I can provide macOS sample captures from both the normal and affected states if useful.

What steps can reproduce the bug?

Open Tibia (Or other QT apps) with Computer History enabled and ChatGPT app open

What is the expected behavior?

No response

Additional information

No response

Start with the Computer History monitoring path and compare the provided normal and affected macOS sample captures. Investigate the Accessibility request path involving NSAccessibilityChildren and QAccessibleQuickWindow::child() while inspecting Qt/Qt Quick windows. Done means monitoring does not substantially reduce the inspected application's frame rate, while excluding the application remains unnecessary.