I saw something like you are describing on a youtube video as well. It's weird. It's the sort of thing that happens when textures are used in a map that are meant for models. This gives off a flickering effect.
But that's not the case here. I made those exterior textures from scratch. So they don't have much in common with model textures. However, it must have to do with these new textures I made. There is one thing I can think of that might be constructed differently in the materials for this texture that might be the cause. The problem is that I cannot test if that solution works as I do not have this graphics problem.

But yeah, when I update the map again I will try to ffix it.