Fiesta mk 4 double locking problem

ive got a problem with my fiesta mk 4 if i double lock from the drivers door using the key its hard to get the door to open and when i put the key in the door it does nothing not even turns i can lock it normally no problem just when i double lock it then i have to put the key in the passengers side but the door handles in the car just keep moving in and out and i have to catch the door qiuck when i see the handle is out the passenger side door is fine if i double lock from that side or if i use the remote key fob any ideas please :frown:

thank you
eap