ford transit 350 2.4 mk6 central locking ?

hi not sure if anyone can advise me please the rear door and side door lock and unlock with the fob no problem .if i try to lock the drivers door and passenger door with the fob they lock and unlock straight away i can only lock them with the key [ i can see both doors lock and unlock ] so if any one could advise me i would be very grateful . stuart

STUART
April 2016