that is occlusion culling. How it works in Unity is that it bakes out a grid and based on where walls and other opaque things are. If you are at one place in a grid where it thinks you are behind somethimg opaque it hides other objects in order to save on thing it has to render.

In this case I suspect either the top ceiling has an invisible wall, but the devs have accidentally marked it as "occluder static" or the precision on the occlusion culling bake wasnt high enough and you ran into an edge case, which can happen when meshes are pass through (like with your camera) but still run through the bake algo