Jetways are not created by GSX dynamically using some kind of code, they are part of standard .BGLs that contains jetways for the airport, so their creation is completely in the hands of the sim, if they show on takeoff, it's means the scenery is correct.
The only thing I can think of, is using the Addon Linker and changing the priorities or installing other sceneries in the Official folder which might have changed the loading order of the packages.
The correct priority for the fsdreamteam-world-of-jetways package should be after all default areas, but before any 3rd party sceneries.
With the current released version, SU9, this can be controlled by rearranging the CONTENT.XML file, but with SU10 (to be released shortly), this file will be gone, and there will be a new way to rearrange areas in the program itself.