A runner that was practicing this for Big20 and wondered is this has been known. I've never seen this before or happened to me and others.

If you have any idea what or why it softlocks. He said that he just walked there and boss fight music just started and never spawned in.

I have had this happen many times while practicing on the powerpak and loading save states. I've never had this happen while running on the actual kick master cart.