Do you just get "Auto Start/Stop Not Available" in the middle of your display? Do you get "Check Engine" And were you using your shift paddles? I had the warning one time only Auto Start/Stop, and I was using the paddles at the a stop sign to take it down to first gear. Then that error came up and stayed on, the car performed normally and I still could use all the functions, just the Auto Start/Stop was turned off. I also checked the A-button on the lower left and the light was not on (indicating it is in off mode (stays running)) until I turned off the vehicle. The next morning error was gone and Auto Stop/Start was working. Manual doesn't state you can turn off the Auto Start/Stop with the paddles and I really haven't tried it again. I have driven the vehicle at least 3K since that happened.
2018 Stelvio TI Sport white/chocolate