Please let us know if you need some more help with this issue.
At release of this sim the fog were formed over time as seen in this video from soon after release 2020.
I posted this image in Dewpoint bug thread.
I have checked a bit and noticed that dewpoint never is same as temp. And i know when temp and dewpoint is same it could be fog. Maybe they simulated that before? That when dewpoint and temp were same fog were formed? If thats true, maybe it’s a bug or maybe they changed the system to not be able to form fog because that would interfare with METAR that reports high visibility?
Well, the weather felt much more simulated overall back then. Hope Asobo get that feel back again 
I think the weather were amazing back then. Never thought that would be possible to achieve in a flight simulator. Too bad it were not accurate all the time. In my opinion it were accurate enought. I also know forecast models will get more & more accurate over time.