The jittery camera is a little overwhelming, think you can fix that by moving the camera moving logic to the same loop as the player's ( If the player moves on FixedUpdate move the camera on a FixedUpdate too, if you're using cinemachine cameras it has a dropdown for this! )
I was also unable to enter the room on the bottom right, the black door was solid, and even though there are no walls on the sides and I was free to go out of bounds I couldn't bug my way inside the room