Gateway airports live in two locations in the X-Plane install folder: 3D airports live in Custom Scenery, while 2D airports live in Resources. X-Plane 11.33 now includes all airports in the Custom Scenery Global Airports folder.
This could cause issues with how your Custom Scenery pack displays. We saw this with the KSEA demo area — the 2D non-customized Gateway pack suppressed our KSEA Demo Area pack for some users.
We are fixing this for X-Plane 11.33r2, but as a general recommendation: please make sure that any custom airports you have installed are higher in the scenery_packs.ini file than the “Global Airports” pack that comes with X-Plane. This way the gateway airports won’t hide your custom scenery.