You don't say where you are located when this happens
- If you are located outside a parking, it's entirely normal that GSX would ask you where you want to park, that's how it works and it always worked
- If you are located in a parking, but you still see the parking selection menu, it means there might be a problem with the scenery AFCAD, like another AFCAD in conflict. The most common source of conflicting AFCADs are those that come with Traffic products, that are supposed to "enhance" default airports, but those must be removed if you use a 3rd party airport. You can check which AFCAD is in use, by opening the Parking customization screen and check the name of the file in use.