I tried everything, nothing worked. Reset bluetooth, audio, nothing.Well, something similar. Playing CoD with bluetooth headphones, when connectimg the cable to charge, sound disappears. I have to switch off/on bluetooth and sound back to normal through bluetooth.
Hope it helps.
In my case, the phone gets completely frozen after trying to play any audio, to the point where I can't even turn the screen on or off.
I've just flashed another A12 ROM, the problem went away. Bummer, because I was really liking this ROM :/