Aha! It just happened to me again. After completing the loading I requested push/start and expected to see GSX ask me for the turnout direction and it did acknowledge my request for departure but then went dead. I was too busy trying to meet a departure time slot so didn't check the log. I just restarted COUATI and everything worked normally from thereon. This was the PMDG B744 at Canberra, Australia, using my newly modified dual gate configuration. I suspect that somehow simconnect channel was overstressed however that airport had very little traffic but I do use the "insane" setting for passenger loading and today I had 333 to watch as they traveled down the glass corridor. I did not notice any stress on the frame rates, however. I am locked at 35 but unlocked it usually operates in the neighborhood of 80-100 at complex airports, 150-200 in cruise but simconnect channel could be the choke point. Umberto has proffered that explanation on other such matters. Fortunately, it is only an inconvenience and doesn't cause a CTD or a lockup so far.
Craig