Please CHECK the "autoflatten" in your .fpe model files (MUST BE Deactivated --> "autoflatten=0") !!!
At every version of the GG upgrading, 80% of the buildings or other assets still have the "autoflatten=1".
You can see the difference of my work on those attached pictures. I lost lots of buildings arrangements
and the terrain while constructing my map with that BAD "autoflatten=1"
(and here on the photos it's just few of looted lost of buildings arrangements).
Two days of my map work was vanish because I've used just one of building who still have "autoflatten=1" in their fpe file
Please read more about the "autoflatten" option at: https://forum.game-guru.com/thread/213020

yh autoflatten is more annoying than useful, it should be kept but always off by default imo (unless it's a huge building maybe)
weird though that it flatten so much... it's meant to be a tiny area around the model only... i've certainly never seen it do anything like that before.

Indeed, THAT's THE "HEAVEN" of the "autoflatting" option users
... but if the user change the "scale=50", "scale=150", or what ever "scale" he need of that model, as example....
all map will be going crazy, even if the autoflatten=1
was used only on the some of "particular" and the one of that "perfect model", imo...
BTW: the "F1, F2, F3 or F4" options, will got the same wrong map results with that "autoflatten=1"