Manage Child's Contacts does not work from Screentime

We just set up my wife's old Iphone 8+ for our child, after a factory reset. We enabled Screentime, to be managed through the Family organizer, which is me. I'm noticing that the 'Manage Child's Contacts' feature does not work at all. It's enabled, but on my child's device, they do not see any contacts I add. Also, they have the [+] button in their iCloud contacts list, so they can add contacts as they wish. Then, from iMessages, they can send messages to any number it seems as well as the contacts they add.

Can you help me get this feature working? I have seen others voice similar complaints from years past, so I did try to turn screentime off and on again on both devices, but it didn't help