I have just bought on Xbox S series, Train Sim World Rush hour deluxe edition. It says in Xbox store that I own it, but all that has downloaded is the original Train Sim World 2 that I already own on PS4. There is no rush hour content at all. Thanks in advance.
Press the Menu button on the game tile of the Xbox home screen, select Manage Game and install all add-ons from there. The Rush Hour Deluxe Edition should include the season ticket. You should also see ownership of the respective content in the store and can install from there.