Got the 'Drivetrain Malfunction' alert about once every 6 weeks:
I just feel a limitation of power (I'd say 50% of maximum output) and it happens in a very smooth manner. I can keep driving at 70+ mph and take my time to park and restart the engine. Everything gets back to normal with no error code to be found when checking through the OBDII port.
I could not find any logic to this (car not running hot, not at 100% throttle...) and I have not had an issue on the track or AutoX so far. I ran the car full out for a one hour long session at the track with 90F ambient temperature last week and it did perfectly fine
Since I am running a tune and exhaust, I am not asking the dealership to look into this but the issue does not bother me much either.