Don't use any Orbx software of any kind. Only running GEX, UTX and REX 3 Essentials Plus w/Overdrive as far as textures. Do also have Vancouver Plus V3 and Victoria Plus.
Then your problem is caused by another of these addons. As discussed in the other thread, the only way to find scenery conflicts is to disable sceneries, one by one, and test, until you find the offending one, which is how the other user found the other issue.
The screenshot I posted in the other thread I linked, shows it's not a problem of the airport, since it doesn't happen when using only the default scenery.