Sand swept tomb music?

I dont know if this is a common bug or even intended as it is but When I play Sand swept tomb I never get to hear the mirage of dust soundtrack, wich is supposed to be the dungeon theme. Instead I just keep hearing stirring the sands (desert theme). Even when I do /class at the dungeon entrance or inside the dungeon I just get no music for the whole dungeon. The only dungeon room where the soundtrack actually plays is the bossfight against hashr. I find this sad because I really like the miorage of dust music. Is this intended? And if not, is there a way to fix this?