I bought the Xbox One X and the game Forza Horizon 4 Ultimate Edition (as a disc version).
Then activated the free 3 months Game Pass and Live Gold.
Now the Game Pass has expired and I can no longer play Forza Horizon 4.
According to the console, I have to renew the game pass to play the game.
But it is the disc version.
You don't need the Game Pass then, do you?
I also had the problem, but I had Forza as a download. I then deleted Forza and reinstalled it. Have you ever seen if you saved it somewhere?