Matrix c/locking issue
 

Door central locking is key operated (non-fob). Year is 07 with 34k miles on the clock. No issues with locking/unlocking until a few days ago. Now, key into drivers door unlocks all the doors but doesn't lock them all apart from the drivers door. Now having to manually press door lock buttons from inside to lock them all before exiting the car then locking the driver and boot doors with the key. Any assistance to rectify the problem is greatly appreciated.