According to your log:
File C:\Program Files\Lockheed Martin\Prepar3D v4\ORBX\FTX_AU\FTXAA_YMML\scenery\YMML_60cm.bgl skipped, likely too big to be an airport
File C:\Program Files\Lockheed Martin\Prepar3D v4\ORBX\FTX_AU\FTXAA_YMML\scenery\YMML_GP.BGL skipped, likely too big to be an airport
File C:\Program Files\Lockheed Martin\Prepar3D v4\ORBX\FTX_AU\FTXAA_YMML\scenery\YMML_Lib_LegacyModels_P3D.BGL skipped, likely too big to be an airport
File C:\Program Files\Lockheed Martin\Prepar3D v4\ORBX\FTX_AU\FTXAA_YMML\scenery\YMML_Lib_Terminalv3_P3D.BGL skipped, likely too big to be an airport
Folder C:\Program Files\Lockheed Martin\Prepar3D v4\ORBX\FTX_AU\FTXAA_YMML\scenery processed in 0.01 seconds
Some files from the OrbX YMML folder were skipped because they were too big to be likely be an AFCAD. However, it looks like the OrbX AFCAD it's MISSING there so, GSX correctly loaded the only AFCAD available for YMML with an higher priority than default, which is the MyTraffic one.
Also, these two lines here:
Customization file C:\Users\mijev\AppData\Roaming\Virtuali/GSX\ymml-2vjiwr.ini ignored: AFCAD file doesn't match afcad_path entry
Customization file C:\Users\mijev\AppData\Roaming\Virtuali/GSX\ymml-zhs6cy.ini ignored: AFCAD file doesn't match afcad_path entry
Shows you have TWO customization files for YMML, maybe one which was made for the default scenery and one which was made for the OrbX scenery but, since the active AFCAD is now the MyTraffic one, GSX again correctly discarded both, since none of them is matching the AFCAD currently in use.
The OrbX AFCAD should be here:
C:\Program Files\Lockheed Martin\Prepar3D v4\ORBX\FTX_AU\FTXAA_YMML\scenery\ORBX_YMML_APX.bgl