ChalklYne

No idea - I don't export normals from Zbrush. I use either Substance Painter's built-in baker or xNormal

Difficult to tell without seeing the assets but i would not use Zbrush for baking. Xnormal would be a better choice. However you could bake a world object space map in Zbrush and convert it to tangent with handplane, it might get rid of the problem. Start a thread if you need more in-depth help.

Thank for the info!