He Facetimes with friends daily. But I can see he gets many calls to FaceTime that he doesn’t answer from unknown numbers.
I’ll have to figure out a way to block unknown numbers.
I just searched “spam FaceTime calls”. There’s instructions for going in and blocking numbers for FaceTime. Looks slightly tedious, but might work. Is there any possibility he’s clicked on something while in chat? They got into his FaceTime somehow, even through one of his friends.