Transmission Solenoid problems of the 2016 Jeep Cherokee

First time transmission would not engage at a red light, I thought it was somehow my fault. On/off allowed me to proceed. Then, a few weeks later, transmission would not engage after full stop at redlight on a multi lane road with a center median. Was able to stop and restart in 4wd to limp off road, before transmission shut down again. On/off restored function after a few minutes and allowed me to drive directly to dealer. Car �repaired� but hours after return from dealer similar problem attempting to enter a limited access hi-way: transmission disengaged while trying to accelerate. Problem of drive train engaging has also occurred from a cold start, and it took several on/off cycles to engage transmission and get car back to dealer. Dealer has focused on adaptive sensors and wiring harness (because of a low voltage reading), which make no sense to me. Confusion created because with each transmission failure every warning light on the dashboard went off. Reading these NHTSA bulletins, I have seen several similar postings about the power train not engaging, so I know my problem is not isolated. I mentioned to dealer a 2016 grand Cherokee recall for brake transmission shift solenoid, which seems to have caused a similar transmission disengagement my suggestion was dismissed. Car only 1 year old and I have barely had use in last 45 days. We are not crazy, and we have a good basis of comparison that something is fundamentally wrong and still undiagnosed. We own an identical second Jeep, purchased within one month of this one. Second Cherokee is fine. . . So far. . However, on our recommendation my sister in law on other side of country purchased same car withinin a month of our second. Same car and same mileage/year and she is experiencing an engine shutdown problem. Suspect our problems are related.