After a couple of months tearing my hair out and getting unhelpful responses from O2 I spoke to someone today who fixed my problem. A while back I accidentally removed age verification from my kids phones and couldn’t re-enable it. I called O2 and they re-enabled it. However I noticed shortly afterwards that iPhone ‘find my phone’ and Life360 wouldn’t locate my kids phones. I asked O2 through the support chat and they said there was no relationship between age verification and location services, and told me the phone settings must be wrong. After a trip to the Apple shop and a full reset, I proved it had nothing to do with the phone. I spoke to an O2 agent again today and asked them to remove age restrictions to prove it, which they did and hey presto it now works. So, O2, there definitely is a relationship between age restrictions and location services at an account configuration level.
That's an interesting discovery, @Chucklebus - I'll tag in the board admins to see if there is anything further O2 can provide in this regard. It could be that the O2 filters applied to prevent access to nefarious websites when the age verification blocks are in place need a little tweak. (I had a similar thing with Virgin Media child controls some years back, VM advice was to remove child controls to make the website work - shock approach! - turns out it was a particular setting on the Website that had to be adjusted, eBay from memory).
Unblocking age verification on a minor's phone, to re-enable phone location functionality, sounds like a sledgehammer approach.