Static Mesh has weird colour and shading different to material

I have created a static mesh in Cinema 4D that is going to be the body of a tank. IT looks great in Cinema4D, but when I import it as FBX into Unreal, it has these weird green patches and dark shading spots on it. I don’t import the FBX with textures from C4D, I create and apply them in UE4. I believe pictures speak louder than words, so here’s a whole bunch of information. Help is much appreciated!


FBX Import Options

Unreal LIT

Unreal UNLIT

CINEMA4D Modelling Program