Child’s contacts syncing to parent

How do I unsync my child’s contacts from my own? I am the parent on my child’s iPad and his contacts are merged with mine. For example, I have 2 contacts of my mom in my phone. One is under mom (my contact) and one is under Grandma (my child’s contact). Whenever I try to delete his contacts from my phone it deletes them off his iPad. I’m not seeing a way to unsync under my parental controls. He does have his own Apple ID so it’s completely separate from mine.