Well, surely the problem doesn't have anything to do with GSX, which is creating jetways correctly as it should. Your problem is the missing terminal in the scenery, and this can only be caused by another scenery in conflict.
If this was a 3rd party scenery, which required to create an Exclude file with GSX first ( to remove 3rd party jetways ), this *could* have been caused by having set a jetway exclude radius so high that ended up excluding the terminal but, since it's a default scenery, it's not required to create an exclude, so this is unlikely the cause. But if you did anyway, try to remove it.
