Any kind of terraforming, be it a Polygon, a Rectangle or a Runway profile,
doesn’t update in the Scenery Editor anymore. When moving the Gizmo to change
the altitude, the terrain doesn’t raise, but auto-generate GRASS does. I
reported the problem on the Feedback Hub too…
Hello virtuali. Thank you for reporting this. The fix will not make it into
SU6 unfortunately but we were able to reproduce it and know how to fix it. As
a workaround, zooming out and zooming in will force the refresh of the LODs
and you should have the correct terraforming displayed then. Regards, Sylvain
Hi Sylvain, Will we expect SU7 fix for this? Thanks!
Hello. Yes it will be fixed with SU7.
Let’s consider this half of a workaround, since zooming back and forth
produces also holes in the scenery, and other weird artifacts 
Also, this
seems to influence Heightmaps Rectangles too Another thing worth noticing.
While editing in DevMode the terrain, if this problem is present, is
uneditable sometimes, and tends to be unconsistent to a compiled and installed
in the Community folder counterpart. I’m experiencing a lot of small hills and
holes which disappear once installed and launched. Hope you guys can look into
it Another thing worth mentioning is that I’m deep into the heart of the
development of this scenery which already counts a lot of working time, so
dozens of aprons, polygons, terraforming rectangles, custom assets and so on.
But this has happened only after the latest updates before SU6
Yes, in fact, this seems to be a refreshing issue, as moving over the area
display progressively the correct heights.
I will also add that it seems to be intermittent. At least for me. Falloff
distance doesn’t blend well either way still, but a couple of times I have
been able to add terraforming and have it actually work. As mentioned, it does
not update in real time and you have to pan/zoom away. However, recently I
have also tried adding some terraforming to fill gaps or to smooth stair-
stepping in the terrain, which has refused to work entirely. Even with the
refresh trick.