When in 3rd person and running down a hill, the camera went under the map
When in 3rd person and running up a hill, the camera went into the sky

This happened immediately after I downloaded Exp Patch 1.18 #2 (1.18.154875) and loaded in.

I joined a different server than before so I got the 75 second wait timer and got teleported to a different location, I spawned on a hill and then went into 3rd person and started walking up the hill with my inventory open and then I noticed the bug.
I have replicated this exact scenario but I am unable to reproduce the bug.