Objects Cannot be moved on the Z Axis in Map Editor

I am making a map (as aforementioned on a recent previous thread) and objects do not move on the Z Axis (up/down). They do, however, stick to the terrain. As I move them on the X and Y axis, they will stay on the terrain. Here is a video demonstrating the problem:



Any ideas as to how to fix?
--- Post updated ---
I have found a strange solution to the problem. In the top menu, under the Object Snapping Distance, it was 0.01. I quickly just changed it to 1 and it solved the problem. Anyway, hope this helps someone else.

 

i am having same problem. tried this and it doesn't work. any solution?