Hello!
We just ran into a similar issue with the "pause" command not working for bluetooth controls when the speed is >1.0.
The solution was to set MPNowPlayingInfoPropertyDefaultPlaybackRate on MPNowPlayingInfoCenter. This was really only clear after reading the source headers:
// The "default" playback rate of the now playing item. You should set this
// property if your app is playing a media item at a rate other than 1.0 in a
// default playback state. e.g., if you are playing back content at a rate of
// 2.0 and your playback state is not fast-forwarding, then the default
// playback rate should also be 2.0. Conversely, if you are playing back content
// at a normal rate (1.0) but the user is fast-forwarding your content at a rate
// greater than 1.0, then the default playback rate should be set to 1.0.
@available(iOS 8.0, *)
public let MPNowPlayingInfoPropertyDefaultPlaybackRate: String // NSNumber (double)
Apparently AVPlayer thought that the app was fast-forwarding because this rate did not match MPNowPlayingInfoPropertyPlaybackRate. Keeping those in lockstep fixed the bluetooth controls for us.