Anyone else having this issue with games that worked on Gen 1? Chuck's Challenge, Chariot, Ticket to Ride all do it. Gameloft kiddo games seem to be doing it as well. I presume something to do with Android 6.0 or USB internal storage.
Edit: Factory reset without USB didn't help, so it must be the games.
Definitely a possibility that they don't with Nougat yet, have you tried any others?