Lighting issue due to Normal map

Hello there,

(To quickly get the context right, Newcomer here, Im on graphics and now begining with Unreal.
For now, im testing mesh import, shaders and lights before producing assets for a personal project.)

So using Maya, I made this simple cube that I imported and associated on Unreal with a pixel art Brick looking textures that I made.

  • So far, if the material is only using Diffuse and Specular. everything seems to be working as expected.

-When the Normal mapl is added to the Material, the 3D effect appears on all faces, but as soon as i rotate the cube in a specific way, some faces loose the effect and are lightened like if no normal was on. (on the picture, the cubes that are surrounded in red have been rotated )

So here are my questions :

-Is it due to the mesh orientation depending to the UV’s ?
(If so, how do you do when rotating objects while modular building ? how does this works ?)

-Adding the Normal map blended all of the light effects on the Material, is it suposed to look like that ?

I hope my questions arn’t too confusing !

Thanks for your time !