codex - 💡(How to fix) Fix In-app browser comment marker overlay can get stuck covering the page [1 participants]

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

26.422.71525 (2210)

What subscription do you have?

Pro $100

What platform is your computer?

Darwin 25.4.0 arm64 arm

What issue are you seeing?

The in-app browser diff/comment marker overlay can get stuck above the tested page and make the app look like it has black-screened.

While testing a local Mentat app at https://localhost:18086/, the visible page became almost entirely black/dimmed after using a browser diff comment marker. The app itself had not crashed: the app DOM was still alive, the Provider Management dialog text was readable via DOM inspection, and the app's persisted frontend logs showed no new window_error or window_unhandledrejection.

The injected overlay node was:

#codex-browser-sidebar-comments-root

It had a very high z-index:

position: fixed; inset: 0px; pointer-events: none; z-index: 2147483000;

Because the overlay is visually above the page, it can make frontend debugging very misleading. It looks like the tested app black-screened even though the issue is the browser tool's annotation/comment overlay being stuck.

What steps can reproduce the bug?

Uploaded thread: 019dddc4-5ec1-7b73-8893-9db3063aefec

1. Open a local web app in the Codex in-app browser.
2. Use the browser diff/comment marker UI to attach a comment to an element on the page.
3. Continue interacting with the same in-app browser tab.
4. Observe that the page can become almost entirely black/dimmed.
5. Inspect the page DOM: the tested app is still mounted and functional, but an injected #codex-browser-sidebar-comments-root overlay remains fixed above the page with z-index: 2147483000.
6. Press Escape; the overlay is not dismissed.
7. Open the same URL in a clean new in-app browser tab; the app displays normally.

What is the expected behavior?

The in-app browser's comment/annotation overlay should not remain visually covering the tested page after a comment interaction ends. It should be dismissed automatically, or there should be a reliable way to dismiss it without refreshing or opening a new tab.

The overlay should not make the page look like it crashed when the underlying app is still functioning.

Additional information

The issue was initially misdiagnosed as a frontend crash because the visible page was almost entirely black. Checking persisted frontend logs and DOM state showed the app had no new runtime error. The injected overlay was outside the tested app's DOM root and used a z-index higher than any reasonable app UI layer.