2006 BMW 750I drivetrain & axles problems

Have a 2006 BMW 750I and was out running errands. I stopped at the dry cleaners to get my clothing. I only turned the vehicle off for about 10 minutes while I went inside the dry cleaners. I paid for my items and went to restart the engine but when I put the vehicle in reverse no movement happened. I shut the vehicle down completely and restarted it. I put the vehicle in r for reverse and it switched back to p for park. The vehicle again was turned off and restarted and it did the same thing nothing.

Over the last 4-5 years, have had multiple transmission related issues. There have been 6/7 transmission oil leaks that had to be fixed and refixed. 2 guibo joints have been replaced over this time. Over the last year and half, the transmission failure light has come on 30+ times when stopped on the road. Upon accelerating the car jerks into gear and moves forward. Twice over the last month, the car was stopped, engine running, and in park.