Randomly flashing content when displayed on top of animation

[loukhin]

OS/Platform

macOS

Installed

OS/Platform's package manager

Version

Version 144.0.7559.96 (Official Build, ungoogled-chromium) (arm64)

Have you tested that this is not an upstream issue or an issue with your configuration?

• I have tried reproducing this issue in Chrome and it could not be reproduced there
• I have tried reproducing this issue in vanilla Chromium and it could not be reproduced there
• I have tried reproducing this issue in ungoogled-chromium with a new and empty profile using --user-data-dir command line argument and it could not be reproduced there

Description

Randomly flashing content when displayed on top of animation

How to Reproduce?

1. Go to https://www.convex.dev/
2. Minimize browser window size to about 1500px
3. Scroll down to "Loved by developers" section
4. Align "third-party cookies" popup with the scrolling feedback (see screen recording)
5. Sometimes it doesn't happen, it should happen after a couple refresh

Actual behaviour

The popup start flashing randomly

Expected behaviour

Nothing should happen, the popup should display normally

Relevant log output

Additional context

sometimes it also happen without the popup-ness, like animating gradient would randomly flash but i can't seem to reliably reproduce it

(edited: nvm, i misread the checkbox)

i can't upload the video directly on GitHub so here's the video on YT
ungoogled-chromium: https://www.youtube.com/watch?v=3w9BMbzOzcw
chromium: https://www.youtube.com/watch?v=tx5Uig40pj8

[loukhin]

disclaimer: LLM was used to diagnose and figuring out what might cause the issue, I obviously don't know what I'm talking about

I try assigning Codex to find what might cause this issue by looking at patches, After some back and forth and some experimenting (using launch flags without building from source yet) it seems like the issue might be from removing gpu_shader_cache or at least from something related to metal.

What I observed:

• launching without GPU or with GL (--disable-gpu or --use-angle=gl) and I can't seem to reproduce the issue, albeit the browser painting became slower
• launching with Metal (--use-angle=metal) and I can easily reproduce the issue