Bad shading of UV islands

I have a problem with shading in unity. I have following object in max (here with applied Normal map, standard material applied…):

But when it is imported via .fbx or .obj or .max format into unity, It causes troubles with shading ( every UV island is shaded differently):

I tried every change every options in Unity for this model, but nothing helps.

Does anybody know where the problem is?
Thank you very much.

it could be that the default lighting in Max is different from the light source in unity. This is honestly the only thing i could think of it being