Since my HTC M9 (stock firmware, region EU) updated to Android from 6.0 to 7.0, I have 2 problems. Not that I have these problems with V2 & V3 (703)...
1) Sometimes the player does not start playing when connecting to my bluetooth set (passive BT set with A2DP functionality)
2) The player sometimes start with very low volume. Then, if another app plays a notification (ie Whatsapp, Fb messenger), or if I press a volume key once, Poweramp plays at the set volume again.
3) The button controls sometimes do not work, the I have to deactive & reactivate the option in