Hi.

I tried using this mod, and when I have the fog option on, fancy fog or not, I can see the sky through the fog. With it off, there is no issue.

I was also getting the same problem, it seems to be an issue between void fog and sodium

The only things this mod changes are the colour and distance the fog starts at. Any rendering issues is probably on sodium.

I am having the same issue. You can see it a lot in the Ancient Cities