This has been a chronic problem throughout SkyMaxx versions. Enclosed is a link to a brief video demonstrating it and then making the same quick flight in default weather. Leaving aside all the advantages of SkyMaxx's cloud depiction, it seems to me to be utterly broken in this respect.
Scenario is as follows. On the ground in fog or low overcast. Climbing does not put you into it. Instead, the layer recedes away from you and vanishes beneath you. It works in reverse on arrival. You descend from clear skies, with a clear view of the ground, into the same conditions--and this is important--without EVER descending through ANYTHING. Performance considerations aside, X-Plane, on its own, renders this just fine.
Getting this right strikes me as fundamental. Otherwise, practicing IFR procedures which, as you know, involve decision altitudes, becomes pretty much impossible.
Here's the short video and, attached, are my log.txt and METAR.rwx.
Best,
Marshall
METAR.rwx
Log.txt