Screentime password no longer works iPad

Unusual situation - I removed my son from family sharing, now I am trying to reset his iPad (for my own use) and each time I attempt to reset, as well as asking for iPad password, it also requests screentime passcode. His Apple ID is greyed out so cannot sign him out.

The screentime passcode entered is correct, however it refuses to accept it.

I have tried to restore the iPad - which updates normally. This now allows me to turn off certain things like 'find my ipad', however the sign out button is inoperable.

iPad 6th Gen iOS 14.6 Model MR7F2X/A

Is it bricked?