Automatic door lock system

I just purchased a 04 X-Type.

I am having issues with the central locking system. The car will unlock fine with the FOB, but I have to press the unlock button several times for the doors to unlock. When I press the unlock on the FOB, most of the the time, only the lights will blink showing the system is getting the signal from the FOB but no unlocking. Other times, the horn will sound and then the doors will unlock. Other times, there is nothing when pressing the unlock button on the FOB. I also tried the key in the driver’s door lock itself with the same symptoms. Inside the car, the chrome door lock latch will not work at times either. I replaced the driver’s door lock actuator today (used) but have the same problem. I was sure the original actuator was bad. I’m at a lost. HELP!

Richard