- Your BaseColor and Normal should be always 8 bit before importing.
- If you import a texture as 16 bit when you add it inside a material it’s set to “Linear Color”, And then if you make it 8 bit and reimport the texture, you should go inside your material and change your texture from “Linear Color” to “Color”. It should automatically do it for you, but sometimes it doesn’t.
- After importing your Roughness, Metallic and AO, open them and uncheck sRGB then you will get correct reflectivity as in substance painter/designer.