Why is my texture a lot darker in one part of my mesh? I am currently facing a problem with my texture. I have created a very simple Object and added some textures to play around with. As you can see in the following screenshot the upper part of the model displays the texture a lot darker than the part below:

Below you can find my node setup. The texture itself was created outside of Blender. The face normals are checked and look like I would expect them to look.

Also nothing special as you can see. The texture itself is created procedurally and does not have any difference in brightness.
Can anyone give me a good hint as to what's going on here? I can really not understand why the upper part is displayed so much darker. I am using Blender 2.91.

The file: https://www.dropbox.com/s/wb6iz1vtmgj0kks/Pillar.blend?dl=0
It looks like your normal map 'color space' is set to 'sRGB'.
Normal maps (and other maps like roughness) need to have their color space set to 'Non-color'.