u/Few-Negotiation4195

This has happened twice now. All seems fine, I stop the car (braking). It stops, stalls, will not start. Put into park to start, won't start, and won't come out of park when I needed to roll it out of the way in a parking lot. Try pushing the button, nothing. Push without brake and it goes into accessory mode. Push again, goes off. Push brake, and start button, started fine. Had battery and alternator tested, they are fine. Thoughts? Anyone else experience this? One mechanic friend thought it might be the "crank sensor", whatever that is, but couldn't be sure unless it was currently failing. Intermittent issue, so I am afraid of driving it until resolved. Help? I hate to take it to a dealer, they are so expensive.