If the lock box is hanging in a vertical position and the front door remains open, it will not lock.

However, if the front door’s prongs (A) touch the inner locking mechanism (B) - which happens easily from a horizontal position - the box may register that action as having closed the front door.

To fully close the front door if it has locked while open:

1. Wake up the box by pressing any button.
2. Either tap the key that appears on the Locks tab or the “Unlock Door” button in the Lock Details screen in the Vault app, OR punch in your Primary Code.  

3. The box will click and the front door light will turn green.
4. Shut the door fully.