Automatic Transmission Control Module problems of the 2013 Ford Explorer

On two separate occasions, the car stalled after DE-accelerating to a stopped position and made a "clunk" sound from the transmission area. During the first event at a traffic light, a very noticeable "clunk" was heard that sounded like the transmission. The car was re-started and seemed to drive normally. To be on the safe side, we brought the car to the dealership to have it checked but they could find nothing wrong. During the second event at a stop sign, another very noticeable "clunk" was heard from the underside of the car and the car actually shifted so that it was felt by the body. After re-starting the car this time and placing it into drive, this time the car did not move when pressing down on the gas pedal. Instead, only the engine revved up. In addition, when putting the gear into the reverse or drive position, that loud "clunk" sound and the physical shifting of the vehicle also happened. Because the car would literally not go, we called for a tow-truck and took it to the Ford dealership. At the dealership, a customer care rep and a technician came outside to look at the car. When putting the car into reverse and drive, the same "clunk" and shifting of the vehicle was observed and acknowledged by both men. However, at this point the car would move forward when applying the gas. We left the car at the dealership for evaluation. When following up early the next week, ,we were informed that they had driven the car about 100 miles over the course of three trips and the car was running normally. Also, we were told that the diagnostic/evaluation of the pcm and transmission did not show anything was wrong. In my opinion, there are two problems here: #1, the stalling/transmission problem and #2, the inability to identify the problem for such a major event.