I'm struggling with implementing AVS support in an iOS app. So far I can authorize and process SpeechSynthesizer events/directives. Currently I am working on AudioPlayer support. I am able to get the stream and play it, then send the "PlaybackStarted" event back to AVS.
The problem is that AVS doesn't seem to recognize that my device is playing any song. For every playback command sent with SpeechRecognizer event ("next", "what is this", etc.) I receive answer, that Alexa wasn't able to change playback state, because it's not playing anything.
At the same time I am able to change playback state (e.g. skip songs) in the Alexa iOS app. All directives arrive correctly via downchannel.
Is there anything more I am missing? What has to be done to make Alexa notice that something is playing?