FSX Cannot get airport at the specified altitude (solved)

I am making a non-stock airport for FSX where a real gravel airstrip exists, it is coming along well considering it isn't photoreal.

However, The airport is according to the aeronautics web at 11.72 meters. Originally I was having a problem in that it appeared elevated in the air so I dropped it to 2 meters. Then I somehow fixed the issue.

In the new design I used SBuilderX with both an AB_MaskClass_Exclude_Flatten at 10.4 meters and an overlapping LC_Airfield polygon at 10.4 meters as well (the AB was showing in yellowish rather than green).

With FSX Planner I created the airport, and in it I set the Airport Data (ARP), runway altitude, start location altitude (two in runway one in helipad) to the same altitude as in the terrain tool (10.4 meters).

The problem is than after I deploy all the stuff and start FSX the airport (runway, vehicle paths and helipad) are all sunken at about 3 meters and then at some point AFTER the end of the runway it rises stepwise to 10.8 meters. Why is my airport sinking down and ignoring my flatten and airport data altitudes?