MJT Is there any update from the developers if it will ever be fixed?
As far as I know, the screen recording functionality's code has never been touched by GrapheneOS developers. All of that is from AOSP, so if there's a fix, it would likely come from Google.
That said, I'm not sure what the issue is here. I never use the feature myself. Audio never works? Or audio doesn't work when another app is accessing the microphone? I did see a feature request about the second one.