I’ve noticed that aircraft on remote stands won’t depart if not all pax have boarded. I have the option in Flight Planner set to “Depart Anyway” or something like that, so the aircraft using gates depart at the scheduled time regardless of if all pax have boarded or not, just not the case with remote stands.
For now, I just dismiss the aircraft manually, if I notice some pax have missed the bus, but in a large-ish airport with separate terminals, I don’t often see it until hours later, then the airline gets pissed with me and my rating drops.
I have not yet bug reported it yet, thought I would post about it here first. I see that this issue was brought up in May or so last year.