You don't say:
- Which scenery you used
- Which parking you were on
Also, you can check using the "customize parking position" option in GSX, if there's a jetway there. If GSX says there's a jetway there, it means there's a jetway, which you might not see, because your Scenery Complexity setting is too low for that jetway to appear.
If there's no jetway listed in GSX, a Passenger Bus will surely park there, unless you explicitly enabled the option to disabled it in that parking, in the customization dialog.
