Hi,
I checked the latitude&longitude of some Taxiway joints in "Ann Arbor Municipal airport" in Xplane 11. It turned out that the coodinates given by Xplane is not the same with that from Google Map, which uses WGS 84. There is about 8 meters offset.
I wonder how accurate can Xplane locate (especially for the airport maps). And what global reference system are you using?
Best
Huaiyuan