Thanks for reaching out to us about this.
Just to confirm, is the issue that, when you switch media on your phone from Spotify to a video (e.g. on Facebook), the playback switches from your AV player to your phone?
Could you also let us know if you use the Pioneer Remote app when controlling playback?
Once we have that info, we'll be able to look into this further.
Thanks! We'll be looking out for your reply.