Ok, after multiple tests, the moon problem in FOTRS 1.3 is solved by copying vanilla 2 moon files in Shader/Sky.
The 2 DDS moon files in Texture/Tex have nothing wrong. They are even better than vanilla. One of those DDS file (the moon halo) is not 512x512, but it’s no problem. My guess is they put it in 1024x1024 to avoid the awful moon halo banding.
All is working nice just by putting back vanilla Shader/Sky.
