Biting my resident dog. Anyone else experience this?

I’ve had my 11-week hound for almost two weeks. She is biting the daylights out of my senior beagle while they play and he isn’t putting her in her place. 80% of the time, the play involves toys or is mutual and the picture of positive. The other 20%, I end up intervening because puppy is biting his neck or cheek and I don’t like it. He is looking at me and I feel like puppy is a bully. She is clearly play fighting and does run for her life sometimes, only to surprise attack a few seconds later.

Has anyone experienced this? Is it normal? What did you do?

Side note: they are not left alone together