Yes, I read the guide. I've downloaded six airports that authors submitted with SAM parking places so I think it would be unusual for all six airports to have the wrong coordinates for compatible aircraft such as the default 737-800. I've also used the X-plane map to slightly adjust the position of the 737-800, but this did not work. Is it correct that the grey A only appears at airports with SAM moving gates? Also, none of the airports show a marsaller at any gates.
Using your static aircraft, if the plugin is working properly, should static aircraft be connected to gates?
SAM.log
Log.txt