@Roland Do you know if this issue has been addressed or resolved?
I run a coop server over steam. I am the server, my wife and my friend connect to my system. when the horde comes on the 7th day, they get a little bit of fog, and its gets a little darker. The can see maybe 16 m away. I on the other hand can barely see my feet. the fog is so thick the lantern 4 <meters> blocks away is completely not visible.
Same thing with storms and weather effects. the connecting players seem to be doing fine, but the coop server gets blinded with overly heavy visual effects.