Also found the same issue here http://www.openradar.me/FB8561088#ag9zfm9wZW5yYWRhci1ocmRyFAsSB0NvbW1lbnQYgICA2qbY-ggM

AVPlayer is not properly deinited and continues playing in background when AVPictureInPictureController is used for pip mode. Manualy removing all strong references to AVPlayer does not help

Guys try this instead, helped me, using layerClass seems to be an issue, not sure why this works though