It's not clear what do you mean with "the Airports".
If you mean non-default airports, as explained in the manual, Page 7, GSX Jetway replacement files should be
Disabled for ALL your 3rd party airports, because GSX jetway replacement is only meant to happen at DEFAULT airports. Quoting the manual, same page:
It’s very important to keep in mind that, in almost all situations, the GSX replacement jetway files must be disabled if you use a 3rd party airport, because these
files are only meant to be used on default airports.
When you first install GSX, it automatically disables all the 3rd party airports
it can find, but if you install a new airport after GSX, you must go back to the GSX Config page and use the "Exclude 3rd party" button again to let it automatically exclude the new airport or, if it's not recognized automatically, exclude it with its code manually. Quoting the manual again, same page 7:
If you install a new 3rd party scenery, just installing it won’t result to automatically go here and reconfigure Jetway Exclusion, you should develop a habit to always check the GSX Config page after installing a new 3rd party scenery. Failing to do so, would result in Parking conflicts (visible as double Parking spots in the World Map), and Jetways malfunctions.
The manual also explains why some airports might not be recognized automatically (because their package names don't follow the official naming convention, common with freeware), and the manual also suggest this, if you
mostly use 3rd party airports.
SUGGESTION
If you never use default airports and you always have a 3rd party add-on for any airport you fly into, you might consider Disabling ALL GSX Jetway replacement files at once, by clicking the >>> button on the Enabled side, so they will all go on the Disabled side, and eventually Enable an airport, for that time you want to use the default scenery.