I have just tested this airport (FAOR) myself and I am unable to replicate this problem.
I have a clean install of Prepar3D V3.2 with all of the NMG Airports, including FAOR installed. I do not have any payware aircraft, so I copied the default FSX Boeing 737-800 and Boeing 747-400 into Prepar3D V3.2. I then did two push back test; one with the B737 and one with the B747. Both tests completed successfully with no issues at all.
If the problem is with the scenery package, then many more users would have had the same problem, including myself just now. If the problem was with GSX, then I would also have had the same issue.
Regards,