henry,
I suspect that you have discovered a very unusual problem. I have not encountered this issue with either Apple or Android devices..........and if anyone is likely to mess up music transfer (or other bits of tech) it is me.
SWMBO is rather keen on Classical music, so my tiny amount of IT cred about the house depends on me getting that bit right.
Is it possible that somewhere deep in the mystery that is IT, you might have put a tick in a Random Play box somewhere?