Yeah - it’s a bit hit and miss I find.
Sometimes it does it and other times it does not ?.
When you leave the seat smartly and pop the drivers door, the car then has dropped out of ready mode.
But the radio etc is still active as we know.
Why is another story, for another thread, but there you go.
You close the close and hit the fob to lock the car and you hear the bong chime, sometimes.
Is it just because there is some type of system “lag” when the car is unsure if you intend to want to drive away again or not ??.
Locking the car interrupts the delayed thinking process and displays its discontent by bonging at you

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Of course all of this is pure guess work, but I have noticed that if you leave the car, then close the door and either pause or do something else, then lock the door with the fob, it tends not to complain.
Why - Because it has even given time to understand what is going on.
Does that support my theory of a “lag” of the system then

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Same if you close the motorised hatch.
If you hit the fob to lock the car at the same time as it latches, it will protest !.
Let it fully two stage latch, wait a short time, then lock the car with the fob, no protest from the car.
It’s had time to catch up.