Yeah I have the same problem with all non jetway stands. GSX keeps telling me to open Exit 1 & 3.
When GSX calls a door using that generic name "Exit 1", it's an indication the airplane is not configured.
The reason why the internal configuration that comes with GSX for all PMDG 737 versions hasn't been loaded, is because you tried to create a custom configuration yourself BEFORE we released the standard one, and PMDG planes won't work without our base configuration loaded first, but yours now is taking precedence and doesn't work, because you started doing it before the internal one was added.
- Be sure you have the latest GSX update installed, which comes with configuration for all currently released PMDG 737 variations.
- Open the airplane configuration editor, RESET the config, so it will show only "using internal database"