As I've said, GSX reads the AFCAD so, if the Marshaller guided you too far, it means one of the following:
- The parking center position as defined in the AFCAD is wrong
OR
- The wrong AFCAD is used for that scenery
You can check which AFCAD is in use, by selecting the GSX option to customize a parking position (any one) on the airport, the dialog box will indicate which AFCAD is now active.