Welcome to the world of cars equipped with computers and related electronic controls. For your sake, I hope the problem is fixed by realigning the PNP switch. If you can temporarily fix the problem by disconnecting the battery, and reconnecting same, then you are not dealing with a mechanical defect in the transmission. Your description sounds exactly like a failure in an electronic control. Perhaps a memory was corrupted. Perhaps an overvoltage destroyed an electronic component. Perhaps a multi-pin connector is not working as it should. Cheer up! You could be sitting on an airliner that is pointing down at mother earth, controlled by a wayward computer. Count your blessings!