This has been explained so many times on the forum. Whenever you see GSX not loading the correct airport, it's NEVER a GSX problem, and it's ALWAYS a problem of scenery conflicts, and AFCADs supplied with AI Traffic products are the most common source of scenery conflicts.
Such AFCADs are meant to be used only as a replacement for default airports but, if you have an add-on airport, they should NOT be used.
Since GSX respects the layering order, you must be sure the Scenery Areas of your add-on airports are all on an higher layer than the AI Traffic product layer. But sometimes this is not enough, and such conflicting AFCADs must be removed manually.