I would not worry about the battery. Not likely to do anything with the msg
I checked the voltage that i started that car today and it was around 14V and after 10-15 mins it hit 15V so you were right about it not being the battery.
I had some spare time so i started & stopped it a few times and the results were all random :/
Every time i started it the lock pin/nugget successfully retracted but where i noticed the issue again was when switching the car off.
First start then stopped opened the drivers door no noise (didn't activate the lock pin), shut the drivers door and reopened it and the lock pin engaged on its own.
Second start then stop engine, open the drivers door no noise, about 15 seconds later with the door still ajar the lock pin activated on its own.
Third start i made with the drivers door still open this time, switched the engine off with the drivers door still open the lock pin deactivated immediately.
Forth start made with the door closed, switched it off opened the drivers door and the lock pin did not activate again. Had to shut the drivers door and open it again to trigger the lock pic for the steering column.
Is there any chance my issue has something to do with the door opening and there is some kind of communication error to the steering column??
PS. i didnt receive the service steering lock column msg today after testing it a few times. So far I've only seen that msg the one time but something certainly is not working correctly with the column lock system.