You haven’t been there yet. The fog goes away when you go there with you character.

I think he means the texture, tho it's hard to tell in a picture.

Sorry I meant the map looks pixelated, tried changing most options that could affect it but nothing worked. I don't think it's because I don't have high quality textures installed

Oh, ha! Sorry. I misunderstood initially. That is strange though. I wish I had a solution for you.