I was trying to add normal maps to my tileset (autotile and tile atlas) and noticed when I added them everything was going dark, so I went and created a simple sprite to try and understand what was wrong, but ended up with the same result.
Without normal map:
With normal map:
The normal map was generated with Sprite Illuminator, and I tried inverting Y as well just in case, but the result is the same. The import settings are default, except for filtering which is disabled.
This happens with single sprites and atlas textures as well (which is why I was getting the same issue with the tileset.
Does anyone have any idea what I'm doing wrong here?