When I go into the room it looks as it shoud be, pitch-black. However, when I put a nanite mesh in the room, here’s what happend, the nanite mesh is giving off light.
I know why I was getting that problem now It’s because I didn’t biuld my lighting. What a stupid question XD, but I’ll leave it here in case any beginner like myself were not careful enough to come across the same issue.