Why does my child's age show incorrect data on Family Sharing?

My son recently turned 13 (his birthdate is correct under his account). It shows him as 13 when I view my family but when click on him it still shows him as 12. I'm trying to add him to my Apple Card and it still thinks he is 12.

I've tried altering his DOB by a day to see if that kickstarted whatever needs to update on apple's side but no luck. Any ideas?

Shows correctly under Family...

Then, when I click on his name, it shows 12....

[Re-Titled by Moderator]