I was having this same issue and just found the fix for it. If you go into the FTX Vector Configurator, the very last tab is titled "Airport Elevation Corrections". Out of curiosity, I added DFW to the list and disabled elevation corrections for it. Voila! Everything is back to normal and looks great. I in turn disabled elevation correction for all of my addon airports, just in case and so far I'm back to normal with all the airports I've tried. I hope this works for you!