@YouTube So straight up, if I can't play music out of a minimized video on my phone then I don't think you guys have the right to make money off of the advertisement you play before AND after videos that are other people's content spawned from their passion.
Monetize Deez nuts.
We'd like to help. Double-tap the "Minimize button" to minimize a video during playback. When a video is minimized, you can browse or search while it continues to play. Also, try signing out and signing back in to see if that makes a difference. Keep us posted.