2022 AUDI E-TRON GT Engine Problems

While backing out of a parking space, with the car in reverse and in motion, the car turned itself off. The car stopped abruptly, I'm not sure if it applied the brakes or some sort of parking brake - at first I thought we got hit from behind - it was very forceful. The car turning itself off and stopping without warning is a huge safety risk, I am glad it did not happen on a roadway. Possibly related, I had started the "Park assist" feature from my phone. I started the engine from my phone, but did not move the car. I entered the car and put it in reverse. I wonder if the "Park assist" timed out and triggered the car turning off. It was about 30 seconds from when the car turned on before it turned off. Depending on the parking configuration, that would be enough time...