If GSX calls a door "Exit 1" or "Exit 2", it's a clear indication you have NO customization made for that particular airplane, so GSX will assume that airplane use the default variables for doors, so it will check *those*
Since 3rd party airplane don't always use default door variables, they need a proper configuration in GSX, which you should do by telling GSX which variable is used by each door, and this supports even the usage of custom variables read with an XML expression. The manual of course explains all of this at Page 53 so, the only thing you need, is to figure out which variable is associated to each door for that particular airplane. That's normal if you use ANY airplane that is not already included in the GSX internal database.
Or, if you don't want to do any of that, just set the door with "Door with no open/close checks", so GSX will just ignore the door's status and perform the service without waiting for you to open the door. Which of course will result in crew/passengers/bags/cargo going through the airplane bulkheads, if you don't open the relevant doors in time.
