Some of it looks a bit flat yet in shadows / lighting. I’m not sure if it’s the materials. But it could be improved by adding ambient occlusion and perhaps a number of point lights in the lower area and balconies. What’s that blue spot on the wall inside the right front enclosure (when facing the central stairs)? It appears that there’s a source of light casting onto the wall or something. In the 3rd photo, a number of the shadows are blue. Are there blue lights or blue materials on the other side of those pillars/walls inside that are not visible in the photo?
Are there post process volumes in the scene at all?