I’m kind of new to unity, so maybe I’m just dumb.
I created a new terrain and wanted to add some heights and depths to it by using the “Stamp Terrain” function. Created a few heights by using the brushes, adding a few depths… Decided to save and - poof - all gone. If I try to add heights again, the terrain seems to be a bit buggy and it create some ripples. Since it’s hard to explain, I took screenshots of before saving and after saving.
Before:

After:

