Why does my mesh looks plastic when Vertex Color is on?

Hi guys!
I´m having an issue with this particular shader.
I’ve modified it to have the option to load vertex alpha and vertex color within the fbx imported. But whenever I check the option ‘TRUE’ the mesh looks all like plastic, or metallic. I’m not very sure why, I have looked a lot of places and options but can’t really find the issue anywhere else, I’m not even sure how to look for the problem.

Hope you guys can see where I’m going wrong with this. Basically I’m new to moving nodes in the shader, I’m just applying logic in here.

So, here are some example images:

Mesh WITH VERTEX COLOR OFF

Material WITH VERTEX COLOR OFF

Nodes

Material WITH VERTEX COLOR ON

UGLY RESULT

UGLY RESULT CLOSE UP

Thanks for your time guys!

I am sorry but your links do not appear to work. Remember unreal is a pbr engine and its looking at light reflectance values to see how smooth or rough the surface is. I would suggest plugging in a roughness value to adjust the metal/plastic appearance. A greyscale image will work as well.