Yes, when leaving the preview, the terrain is displayed correctly, but in the preview, the terrain is not scaled correctly - as i said, the scale of the entire terrain is applied to the tile currently in the preview. It is stretched vertically, in this case.
For example, a structure that should be around ~200m high, compared to the maximum terrain height of 4000 meters, is displayed as being 4000m high.
If i then change some value in the terrain definition settings of the build tab, (changing the terrain height by only one meter, for example) results in a correct representation of the tile's height.
The issue might be caused by the program misinterpreting the terrain definition when entering the tile preview mode, but it is correctly interpreted after changing these settings while within the tile preview.
i might be able to get some screenshots of this, if necessary.
I could also attach the file where i first encountered this problem - though it is just a simple terrain with a mountain range on it.
Edit: i just loaded up the file and made a few screenshots.
(still using version 1.3.0 btw - will update to the new release today, though)
I am previewing the tile at (1, 0) but every tile behaves like that.
Correct scaling, after changing terrain-definition:
Hope that helps.
Otherwise, i am really impressed with GAEA.