Since last auto update Apple TV asks for former owner's Apple ID password on every start-up

Since the last auto update of tvOS, Apple TV has been asking me for the password of the former owner's Apple ID every single time Apple TV starts up. I deleted this information from the device when I got it, and under General > Users and Accounts there are no users other than me. I've seen old instances of this or a similar issue where the recommendation has been to contact the former owner and have them remove the Apple TV from their list of authorised devices, but I am unable to contact the former owner, so this is not an option (and tvOS/Apple IDs should be set up so this is not required, what a ludicrous thing to impose.)

Apple TV HD

Model A1625 (64GB)

tvOS 15.2(19K53)