the answer lies in your door width. If your door is to narrow for the spindle, when you tighten the lock together you are putting to much pressure on the mechanism it, that wont work. The spindle turns without needing power from the inside, its purely mechanical. Your solution could be to get a wider door, add a spacer (make sure you add 2, one on the outside and one on the inside, this way both sides are even, or trim your spindle down, which I do not recommend.