Painter normal map fading issue

Cadu

I was working in the detailing of my asset and noticed that a specific part had a issue in the normal+height map. No matter how i try to paint in that region nothing goes thru that area. In the diffuse map a white stain of some sort appear only in that region.

I used a metallic material preset from painter like bronze armor or copper as a starting point doing several changes after.

Never saw something like that. Anyone has ideas what may be the cause?  

Thanks in advance!

Cadu

Just noticed that a sharpen layer in this preset material was causing the issue.. still don't know why.