How to prevent child from modifying and blocking contacts in Messages while using Screen Time on iPad?

I'm using screen time for child's iPad. Child is able to modify and block the contact he is messaging to and hide alerts. Is there a way to allow the child to communicate by sending messages, but not to be able to edit the contact in such way ?

Also in Communication limits > Allow Contact Editing is off.

[Re-Titled by Moderator]

Original Title: Messages restrictions