Blender to U4 light / shading problem

After export my skeletalmesh to UE4 and placed in the map i see a light problem or shading problem, one of the parts of the weapon have the light inverted, and its the part with different pose between the model edit and the pose edit:

How fix that or its a bug ?

Try to export it from Blender using the Smoothing Edge option.

Thanks you, now after change from normal to edge its fixed ^^