AVPlayer will randomly just play audio, not showing the video track...
Playing video correctly with AVPlayer while having an active compres
Just heard from Apple DTS. They also agree this points to an Apple iOS bug and asked me to log it.
I cut out usage of AVAssetExportSession altogether and it solved the issue. So calling AVAssetExportSession in combination with other AV methods is what causes the iOS instability.
In my case I was usingAVAssetExportSession for post capture compression. So instead I used AVAssetWriter to sample each frame in real-time to the format I needed...
This should be fixed soon by Apple, hopefully.