When I made some of these buildings I had my own custom foundation built at the base and used the NoBase shader to prevent the game from auto generating one. Unfortunately the nobase shader makes things look too bright and shiny.

Oh yeah, and, if it's any help, the LOD model doesn't have this problem.

I want to use this, it looks great, but it appears to have some sort of weird glow-in-the-dark thing going on with its shader. Screenshot: https://imgur.com/a/F13ZoL7