If the lock slowly started to lose power speed locking and locking or would stop working intermittently and start again the motor actuator is most likely to blame.
Vw golf one door not locking.
It is very easy to test to see if this is the case.
There is no door mechanism by the way all door lock unlock functions as well as the electrical functions of the alarm system are handled by the latches.
One door lock is not working.
On the good side of things if you have time on your side it sounds like a micro switch which is pretty cheap to replace.
If however it does not it could be one of a few different issues.
Yeah sorry t be the berer of bad news but no if it is the dame as a skoda it s all micro switchings and smoke.
This is a common problem on vw vehicles built 1999 present.
I have 2008 mk 5 r32.
This is my first post here although i read thing here for the past 4 5 years.
Now it s my turn to contribute to the common knowledge.
The only way is to pull the door lock latch mechasinm out and deal with it.
Be it the switch for that side latch or actuator.
When one door has the locking issue it is likely an issue within the door.
A few youtube videos exist for this.
At one point the door was lock shut and it remained like this for quite a while.