iPhone Messages shows 'Ask a parent' error after iOS 27.2

Since the update to 27.2 I get a problem where suddenly I can't open individual messages anymore, I get a screen saying "Ask a parent or Guardian to Approve This Person". Before anyone says the obvious, I AM the parent account, this is NOT a child account (Though I do have a family group with kids, that I am the Parent on). If I click the "Ask to Approve" button I get "You account is not configured as a child or teen account", which is correct, but yet I still can't access my messages.

Here's the strange thing. I reboot the phone and it's fine again for maybe an hour or so, then I get locked out again. I completely logged out of my Apple ID on this phone and then logged back in, it worked for a few hours and then back to the same issue.

I have screen time completely turned off on this phone, there are no restrictions turned on etc. This only started happening after I installed 27.2, the previous iOS 27 was fine and this occurred within an hour after updating.

Is this just some weird new bug that I've tripped over?

[Edited by Moderator]