Let me add to this thread, having the same problem described here (GSX hangs in the loading baggage status after loading PAX). For me, this started right after I ran the FSDT Live Update last week. It happens every session, in the PMDG NGX at any location. My flow is to first request catering, then I set the payload value and then request boarding. Boarding completes and the loading xxx of 160 passengers messages stop. Using Shift+Ctrl+F12 to pull up the GSX window it indicates baggage loading in progress or something like that. And then nothing. Of course reset coatl clears that and I can start push back.
Cheers.