I am not speedrunner but just wanted to share in case this is not a known bug and might be useful to you guys.
had this bug/glitch during my 1st casual playthrough
Thanks for sharing oriHug
I don't know how to do it exactly, but it has happened to players before.
What I did was going to the right and dying few times as I didn't have the burrow ability yet at that point in time. Then my spawn point was in the middle of the room with the bones take make noise to the left. When I noticed I can't make progress to the right, I went left and the animation of stepping on bones played out as if I came from the left. I think I was pressing the down button and cliped. At least that's how I remember it, my inputs might be different but the bones are the key to the glitch I think.