A simple closed cubical room the only difference is that the material has 1 metallic and 0 roughness to see the effect better, the same thing happens to all the items with metallic in the room.
I build a few other rooms like this with different meshes to see if the problem in UVs or material itself but I got the same result. Here the picture of the room unlit, you won’t see anything even if I add a spotlight because of the metallic nature.
