I have an iPhone 12 Pro and have noticed when I play music from my library it’s missing background music. I can’t think of any other way to describe it other than vocals are fine at all volume levels but drum beats or some background notes aren’t there when they should be. And it’s not a fade or balance thing either. The sounds/notes/drum beats just aren’t there or they’re just incredibly soft when I know for a fact listening on other devices they’re there. Strange. Any thoughts?