Terraforming issues at Mykonos Greece island (and not only)

I have noticed recently that Mykonos Island located at Greece is experiencing
significant terraforming issues. I have checked the island after the new
terraforming method and SU12 update and this was not the case back then. I
don’t know what could have caused this problem. Here are some images:

Any ideas what could have caused this issue? -=Manwlo=-

Let me add that when in offline mode the situation is improved. There are no
holes on mountains and hills. However, the coastlines remain more steep than
they should have been. -=Manwlo=-

Just a quick comparison of Mykonos island as @Manwlo said: Default scenery
with default LGMK airport. 1st image is from Bing Maps just for reference. 2nd
image is offline data with new terraforming and water flattening. 3rd image is
online data with new terraforming and water flattening. It seems that online
data are changing the mesh (elevation data, vectors etc.) in a weird and wrong
way. This issue is affecting islands in Aegean Sea and probably other regions.
Appeared after WU13. Asobo devs if you are aware of this issue and you have a
workaround to fix it by releasing a patch or maybe in the upcoming update,
please just let us know. Thanks in