Hello
Blender cant use the roughness and metal Chanel. Its PBR. You need a specular map.
To use the normal map, try your normal settings in Blender. Otherwise your normal map is just a Colormap.
To use Textures in Stack, use multiply on every Texture.
Adjust your Normals with:
edit mode-- A-- strg-N. If all normals in wrong direction, use --flip Normals.
Is there a correct UV?