This happens sometimes


Expected scernario(happens most of the times):

Turn off the car

When you open the door, you will hear a mechanical sound.

Close the door and you can lock the car with the remote


Issue:

Turn off the car

When you open the door, you will hear few short beeps.

Close the door. Nothing happens when you try to lock the car with the remote


Workaround A (works sometimes):

Turn on the car and turn it off. open the door if the mechanical sound is heard, you can lock the door


Workaround B (resolves the issue 100% of the time):

Turn on the car, put ithe vehicle in D. Drive a meter and put back in P

Turn it off and open the door (you will hear the short mechanical sound)

You can lock the door


Any thoughts/help is appreciated


Remote battery is not old

 

You don't say year and model you have or how you have set up your door locking system, there are various ways.
My opinion/guess would be the door lock actuator, or a bad park shift sensor.
The only way to know for sure is to have them checked by a certified tech.