According to CP77: Black scenery in Konpeki Plaza and No-Tell Motel · Issue #632 · HansKristian-Work/vkd3d-proton · GitHub there is a difference between how the Windows drivers and the Linux driver optimize shaders. This results in pitch black illumination inside buildings of Cyberpunk 2077 due to division by zero while doing LUT computation. This seems to be a game bug - but OTOH, NV Windows drivers seem to optimize the singularity away because it’s a fast math mul and div with the same operator, the Linux drivers don’t do this, letting the game bug sneak around.
While vkd3d for Proton now has a work-around for it in DXIL, this should probably be fixed at the driver level to have the same optimization as the Windows drivers do for better compatibility.