Boss Music Bug

Over the course of me playing the game, I've noticed that many bosses (including mini ones) don't play the correct boss theme for their fight. Oftentimes it's replaced by other battle tracks for the specific areas they take place in, for example the Evoker and Enderman. The Monstrosities have this unique case where nearly all instances of fighting a Monstrosity just plays the Copper Monstrosity theme. Kinda sad since I want to be able to hear Peter Hont's music at work.