Jimmy can you explain what caused the icon loss as related to the cloud file, and what was done to correct it? Just curious about it...thanks!
From what I can determine, cloud types used above their altitude range, as listed in the Cloud Editor, are the issue. I duplicated the problem offline by setting some "12k" clouds above that setting at 14k, using drones at a base for icons. I then launched an aircraft, flew up to altitude, flew through the clouds at that level, then dove down to the base, drone icons were gone. Reset the clouds to 12k, repeated the process, drones icons remained visible. Just to be sure, I remained in the aircraft, flew back to altitude again and repeated the process. Drone Icons remained. I tried this with several different Cloud types, it appears to only be a problem above 12k. I did not experiment with the lower altitude clouds.
I am sure Hitech would have a more eloquent way of describing the problem, especially from a coding standpoint.