Normal maps and bump maps serve the same purpose so use one or the other but not both at the same time. Also, Im guessing you are rendering in Cycles? Cycles converts bump maps into normal maps. Some have said there are problems with normal maps in Poser and I would tend to agree because I've had issues with them myself. IIRC you are supposed to set them at a strength of 1.0. This ALWAYS results in way too much bump in the texture. Also keep in mind if you are using PBSDF for your textures that it's roughness is modulated by the bump maps/normal maps. That means the bumpier the map, the rougher/less shiny your object will be.

W10, Ryzen 5 1600x, 16Gb,RTX2060Super+GTX980, PP11, 11.3.740