I use video player (framework MediaPlayer) in iOS application. If I rotate device to landscape orientation, video doesn't rotate to landscape.
There is no video rotation only on iOS 11. iOS 9, 10 - rotates good.
Before start video player and when device is rotating, XCode get message:
[MediaRemote] [AVOutputContext] WARNING: AVF context unavailable for MRAVOutputContextCreateIndependentRoutingContext
What to do for rotating video?
When I delete all the breakpoints，my problem was fixed. Maybe you can try that and hope it also gets fixed for you.