This might be a quick fix, but just putting it out there - I have no idea how to fix this. Thanks!
So you can see the nice brick on the building (this is in Render) in Texture mode…
Looks pretty nice! But then I switch to Rendered mode:
Ew. The texture looks like that bookshelf scene in Interstellar. I unwrapped the object, too!
Yep that’s it