Atlas Won't Load

I have large parts of my atlas that will not load. Parts I have done are under fog and then other parts at the edge of where I am are just grey before the fog. I know this is early access but this is a major issue!!! Makes the atlas useless. I have restarted the game but this seems to make it worse. If I use the burning monolith center that loads but huge parts that I could see before are now under fog.