Issues with Airplay and iPad with IOS10

We use an Apple TV hooked to the projector in our auditorium to present Keynote presentations. Our preacher uses his iPad for this. We have had no issues until he updated to IOS 10 this week. Now all of his presentations the bottom is cut off. I can airplay the presentations from my iMac and it works fine. Any ideas on settings or something we can try to fix this?