Tiviris thank you for sharing this. I was able to reproduce the bug on my own phone just now, so it's not just you.
Unless I'm mistaken, GrapheneOS has not made any changes to the related code, so it would be considered an "upstream" issue, meaning one that AOSP developers should fix. GrapheneOS developers do sometimes fix upstream bugs, but only if they're really bad and would affect a lot of GrapheneOS users, especially security/privacy-related regressions.
There are actually quite a few bugs like the one you found, but AOSP developers usually end up fixing them before too long.