We just posted an update today, which allows to override the airport elevation in the GSX Scenery Customization page.
In the top-right of the editor dialog, you'll see the altitude as read by the top-most AFCAD that has specified an altitude for that airport. By pressing the small "Airplane" icon, GSX will read the current ground altitude, which might change if that airport required a fix. Just press Apply, and all jetways should now go on ground.
This should allow using the airport without disabling it in OrbX Vector.
To get the update, run the FSDT Live Update from the Desktop icon, when the sim is not running.