In the game, if you jump at the middle column of tiles from the right, making sure the camera is locked in place, you upwarp to the top of it if you touch it while falling, and snap to the bottom of it if you touch it while going up, you can also clip past it if you hold right as you touch it while grounded.
what i think is causing it is that is has to do with the camera position, what I'm not 100% certain with is maybe since the player is close to the camera scroll threshold, that it causes problems with collision.
In the game, if you jump at the middle column of tiles from the right, making sure the camera is locked in place, you upwarp to the top of it if you touch it while falling, and snap to the bottom of it if you touch it while going up, you can also clip past it if you hold right as you touch it while grounded.