I tried it in the Unity editor but couldn't replicate it. I'm curious, do you know how high your FPS were? If I know whether it was relatively high or low I can at least rule out a previous problem that I thought I had fixed.
Also, you said the room had started to transition. Could you tell which room it was transitioning to? If so, was it the library or the bottom floor? It's possible, even likely, a trigger might have been a bit too wide and caused a weird placement with a collision bug.
Either way, I'm a bit busy with a new project currently, so I'm not sure when (heck, even if) I get around to fixing it. That depends, was this only when you walked into the corner specifically, or did it happen even when you walked straight towards the stairs or the door?
Hoping it's at least not a severe bug, but at least I'm aware of it now. Thank you for putting the time in and telling me about it. I appreciate it!
I hope you're otherwise enjoying/enjoyed the game.