2008 beetle passenger door lock

The door doesn't lock when using the key fob or the lock button on door. When using the fob the alarm gets set, the driver door locks but the passenger door doesn't lock and if you open it it sets off the alarm. The lock button on the drivers door locks the driver's door only. Since the alarm goes off when opening the passenger door it indicates that it realizes the door is closed. When setting the the alarm it doesn't give the horn beep indicating that all is secure. This tells me it knows the door hasn't locked.