I threw in a material on the walls to see how the color looked with the dark floors, once i changed the scene from unlit to lit i noticed certain parts on the walls in my scene are all black, I haven’t had this problem before and I changed the UVs just to see if that fixed it, but nothing.
It looks like you use movable directional light only…so that means you don’t have any global illumination (or indirect illumination).
Add a skylight to add G.I