cloning problems

[Domojestic]

I have recently unlocked the cloning upgrade, but there is a slight glitch. Whenever I clone a cell (this means all the walls, the door, bed, toilet, light, flooring, and room label) it will only work if i put it directly on some other built object, such as the original cell. if I put it over any kind of empty space (so I can quickly build another one) it says "blocked", which i think is the opposite of what it should be doing (i think its supposed to say "blocked" when put over some kind of built area). could someone help?