Locking/Unlocking doors

That seems to be the clue to your problem.

 

Yes, this is an important clue, as it shouldn't immediately auto-unlock.

Are the door handles clean and dry? Has the car been washed recently? We know that when wet, such as when handwashing the car, the Lock sensing can get fooled and unintentionally lock the door. I'm wondering if something similar (electrical leakage through dust or oily dirt?) is fooling the door handle sensing into thinking you are trying to touch and unlock it.

 

This can be a sign that one or more of the electric actuators which physically moves the locking mechanism is failing.
If you watch the lock indicators closely you might SEE where the problems is.

The system "knows" when all the doors don't lock......and is unlocking them all in an attempt to tell you that things are not working right.

 

It's weird that the lock/unlock only happens with the remote and not with the physical lock switch.

I was thinking that maybe the car was sensing keys left in the car or something and so refusing to lock, but I did a test and the car is happy to lock a set of keys in the car.

 

That would tend to indicate that the physical switch that you were using for the test is the one that is failing electrically.

 

????? Please explain.

The OP says locks are AOK with the physical electrical switch located on the door in the car but there's a lock/unlock problem when using the remote.

 

When the actuator fails, it only moves part way and does not move it's attached button enough to lock.

IF......you are using THAT button for your manual test, everything will appear OK......because the actuator for THAT BUTTON does not come into play when you are moving it by hand.

Now, after typing that I realized that probably isn't the button he was talking about.

When the actuators first start to fail, it is intermittent.
I think I had the same result when mine first started to fail.
Maybe the lock/unlock electrical switch on the door keeps power on the actuator longer ?? Don't know.

 

I interpret the OP as pressing the electric rocker switch that locks all doors of his Liftback, not rolling that purely mechanical roller switch that looks just a single door. It makes no sense lock only the driver door and leave the other three unlocked.

(With the default factory settings, placing a Liftback in Park unlocks all four passenger doors.)

I suspect (based on evidence outside this thread) that it depends on how long the driver holds it down. If so, then in my typical use, it is shorter than the signal applied with the remote.