From what I remember, I was on my way to the lever after the lava where the rock platforms would move in and out from the walls. I fell somewhere along the way and the spinning started. I was able to trigger the “you died” canvas by holding R but it put me back in the same spot and was still spinning, so maybe it was a checkpoint? I noticed that whenever I hit ESC to get control of my pointer back to scroll through the game’s page the spinning would stop, but then when I clicked back in the spinning would start back up again, so it might be an issue with how it’s reading the mouse position?
I’ve never worked with mouse-based cameras tho so I haven’t a clue XD best of luck!