I bought Gamepass Ultimate to play the games on PC that are showcased on the xbox website but in the xbox app undere "All PC Games" it only shows around 200 games (Which are all from the standard gamepass plan and no games from Gamepass ultimate) I contacted Xbox support from the website but they just checked that the subscription was active and then told me to log out and in again which doesn't do anything. Either it's broken or 90% of the things promised when buying Gamepass Ultimate aren't true...
Games from Ubisoft do display in the ubisoft app (Assasins creed, etc.) But are nowhere to be found in the xbox app.