GSX just reads Simconnect variables so, if it doesn't detect a door open/closed status, it either means the airplane is not setting it, or you haven't specified the proper ID (if the door uses the standard method) or the proper XML expression (if the door use a custom method).
Regardless of the above, if you set a door as "door without open/close check", GSX will always ignore its status and will proceed with that is doing.