The main door to my apartment (the one facing the street) has the sort of lock that's built into the doorknob. From the inside, you can lock the door by turning/pressing a small button in the knob itself. (looks very roughly like this
). From the outside, of course, you need a key.
It used to be that if you locked the door by depressing the button, the door would stay locked unless you manually unlocked it by turning that button, even if you went in and out, or used a key.
That is - if I came home to locked door, unlocked it with my key, and closed it behind me, the door would be locked. Similarly - if the door was locked, and I stepped outside and closed the door behind me, the door would be locked.
Now it seems that if I open the door in any way, it unlocks itself, and remains unlocked unless I turn that little button on the knob to lock it. That is: If I come home to an locked door, unlock it with my key, and close it behind me, it is now unlocked and stays unlocked. And if the door is locked and I step outside and close it behind me, it is now unlocked and stays unlocked.
Why would this happen? Is the lock broken? Has is accidentally been set into some sort of different locking/unlocking behavior? I want it to act the way it did before.