One building keeps pasting at sea level

one of the buildings i copied is pasting at sealevel regardless of the terrain i am pointing at. 

I had to use the height command 20 26 just to get it level with the ground.

Once it was where i wanted it a recopied and tried to past again and get the same issue.

Other copies are not having this issue

The plugin was unable to find an optimal height.
I have tried this at a dozen places around the map. no matter where I paste it it puts it at sea level
So this building issue, it can't find a good pos for this one exactly.
i could try sharing the file with you