Thank you guys for the input.
WebM might fix it for some (e.g. only in NewPipe, not in PipePipe), this is a workaround rather than a solution.
I ruled out an app update being the cause, since I tried multiple versions and NewPipe has not published an update since Aug 1st.
Thus, this issue seems to be either:
- an upstream problem caused by changes to AOSP.
- a problem specific to GrapheneOS.
Scenario 1 seems slightly unlikely to me, since there have not been any reports on the NewPipe/PipePipe GitHub regarding this issue.
GrapheneOS might be one of the few OS (excl. Stock Pixel OS) that already shipped Android 16 QPR2 and the only ones that shipped the latest/future security updates – the issue possibly stemming from either of those aspects.
But until someone directly compares NewPipe/PipePipe on GrapheneOS to Pixel OS, we will not know if it is an upstream issue or an issue downstream on GrapheneOS.