Communication Limits in Screen Time not restricting contacts

I have been trying to set up my son's phone so that only approved contacts can contact him but for some reason it's not working no matter what settings I have selected, anyone can call or text regardless of them being in his (or my) contact list.

I have read a few threads saying there was a loophole around this if the contacts were not synced to the iCloud but his contacts are synced to our iCloud which is family shared. I thought maybe it was because he was using my old phone and everyone texting him was someone who had once been a contact previously in that phone, but I have since factory reset it multiple times and have had people text who have never been a contact and it is still not blocking them from being able to text or call.

I have selected to manage his contacts, and it was approved, and under that list it shows the approved contacts. I have also disabled contact editing so he cannot edit his contact list. "During Screen Time" is set to contacts only and "During Downtime" is set to contacts only. Not sure why it's not working but it's suuuuuuuuuuuper frustrating.