My Son is deleting his sleep schedule and unpausing his device somehow.

I don't know how he's doing this. I read an answer to a similar question that he might be changing the name of his phone and then coming back on as a different device but that does not seem to be what's happening as there are no new devices in the list of connected or not connected devices. The device is being unpaused, or the sleep schedule being deleted while the name stays the same.. This happens even when I've paused all other devices he has access to.

How is he doing this?

How do I stop him?

Thank you.