Guys, why are you all missing the point?
His question was about manual terraform, nanoframes had nothing to do with it.
The answer to his question is: You didn't have vision. Look at these screenshots (alternatively, next time check the replay).
Terraform went over completely normal. However, if you don't have vision of the terraformed area (which may happen in craters or behind walls etc.), it won't show you what happens (you don't see enemy terraform through fog of war either).
That's normal and been like this for ages.
Now, continue your discussion about ground flattening for building.