IPhone XS Max, the volume on my phone keeps going to max, without me touching it

I'll be listening to music and all of a sudden the volume goes to max on it's own. it keeps happening. i've rebooted, i've turned down the max volume level (as my ear drums were starting to hurt). any thoughts on this issue? I'm running iOS 14.2 ... also, not sure it if's related. but i've purchases earphones on Amazon (non-apple, but apple compliant). i use the earphones a few times, then the blue tooth stops working, it's happen to 3 pairs, independently. i'm hoping this isn't a similar issue Apple had with the software they created that drained the battery on it's earlier phones (6). Any thoughts would be most appreciated.