Correction to my previous comment, after a session last night it appears that the problem occurs even when setFog is given numerical parameters.

So far on my end the problem has occurred 100% of the time when using setFog/BIS_fnc_setFog on non-local MP clients. Problem only occurs when using the array setFog syntax, numerical values are fine. As far as I've tested the issue occurs regardless of what values are given to the array.