So I have this same issue, however I do not have any FTX Global installed. I have deactivated every add-on to test if there is something that doesn't agree but no luck.
This just came up after a fresh install of P3D, I even reinstalled KLAX and no change. The only time I can see the textures is when I deactivate KLAX.
I'm sorry, but I can only repeat and confirm the problem can only be caused by some other scenery in conflict. That doesn't necessarily be something from OrbX, even an AI traffic product, which comes with addon .BGLs that should be used only with the default scenery, can cause these problems.
But it surely won't happen on a fresh installation.
And, just to be sure, check you set the Mesh Resolution and Complexity as indicated in the KLAX manual, the "Design Notes" section. Try first with the same values (100% Complexity and 10 meters Resolution I think), and not higher.