This only appears to be an issue for those that updated to A11 OTA. Performing a factory reset solves it.
It is highly unlikely that it would not be possible to use the OTA upgrade to Android 11 and that the upgrade to Android 11 would require a factory reset.
Perhaps we will see the moderators start answering again here. One would expect them to be more active after a major upgrade to the A11, but unfortunately the opposite is true so far. But users cannot reply to everything themselves.
@Anders_ASUS@CH_ASUS