[MDL] Drumline audio problem

I'm writing a piece for my high school's battery with the musescore drumline extension, and every time i play back the song or I preview a note, I hear a different sound on top of the drum's sound(such as a whistle or a cowbell) and this happens for all the marching percussive instruments(snare, tenors, bass). I was wondering if anyone else has had this bug and knows how to fix it.