I'm your new PA fan. I just found the clue after face low volume while play with Bluetooth(2) couple weeks ago. Basic info are Samsung J7+ Android 8.1.0.
I found the suspect 2 points here.
1. It shown DVC strike-though as describe in picture attach below
2. another clue not sure relevant to results low volume or not?
I try to DIY fix many googling research such as.
1. Try enabling Disable absolute volume in Developer options of your phone. Most popular suggestion to solve problem but still didn't work for me.
2. also disable