not sure how the door is put together off the top of my head. id pop off the door trim and see if anything is out of place maybe a rod popped off or clip is broken. stick your key in the barrel and rotate it to different positions opening and closing the door, and see if that makes a change... compare the malfunctioning door mechanism to the one on the other front door as well...
when i turn my vp berlina key counter clockwise (driver front door) and pull it out of the barrel it does the opposite of your problem... the lock top cant be pushed down at all, its locked in the open position...
dont sweat the petty... pet the sweaty...