Can't change texture type to Normal Map

I imported a 4K normal Map into unity, I choose Normal Map in texture type in texture import settings, click apply, loads for a couple of seconds but nothing happens, texture type remains default.

 

This Happened to us when we were working on UI. The texture type kept changing back to Sprite.
What helped was renaming the files.
I think some files are forced to have a specific Texture.

 

Whenever you have import settings that you can't change, check if there is a asset preprocessor somewhere in the code which overrides those settings. For example, there could be one which sets the texture type based on a filename suffix.

https://docs.unity3d.com/ScriptReference/AssetPostprocessor.html
https://docs.unity3d.com/ScriptReference/AssetPostprocessor.OnPreprocessTexture.html