Dead bolts get a lot of use from both sides of the door and it is easy for them to become loose. You probably noticed those two screws on the inside of the door holding the locking mechanism’s plate in place? Those are not the screws that you are looking for. Please do not tighten those thinking that it will fix the problem.
Take your trusty Phillips (star) screwdriver and remove those two screws. Please be careful not to lose them, because you will need them again. Carefully remove the plate and locking knob. See that? Inside there are 2 larger screws.
On the exterior door, press and hold over top of where you put the key to open it, on the inside of the door, take your trust Phillip’s (star) screw driver and tighten the two larger screws that I mentioned.
That should do it. Did it tighten everything up nicely?
If it did, put the locking knob and plate back on to the mechanism and put the two small screws back in. Just make sure to test that the door can lock and unlock smoothly.
Now, if it didn’t work. Chances are the screws are stripped and need to be replaced, or you need a new bolt lock. Just give management a call and they can guide you on what step to take next.