Luke wrote:FALL? is this the code? if yes, I will correct the altitude
Yes, curiously, the ICAO is "FALL"

In XP10.21 I was able to find the airport only when searching it by name "Lydenburg". When typing in "FALL" there is no result.
I worked around the bug by enabling "airport follows terrain" in the XP settings and then the airstrip is where it should be.
Edith: I tried to start a flight there, and FSE says: "You have no rented A/C at FACB", so it seems, that the coords are wrong, not the height level.