Why is it not letting me play it when I have the ultimate pass?

It's likely a visual bug and the library hasn't refreshed for you yet. It should eventually update to reflect the removal of GTA V. I have checked this on my end and the game does not show in the Game Pass library. Have you looked on other devices such as the Game Pass app on your phone?

Thanks,
Kyle

Thanks for getting back

I've restarted my console many times, and it still showing up on the gamepass library to this day 6th January AND still says "launch/play" on the title inside the gamepass library tab.

If it's been removed then why is it still showing up in that specific tab showing that it's still there and playable?

Hi Savage. My name is Kyle and I'm an independent advisor.

As recently confirmed by Microsoft, Grand Theft Auto V left Game Pass on January 5th. If you reboot your console, the game will likely disappear from the Game Pass library.

To continue playing this game, you may purchase it from the Microsoft Store. Please reach back if you have further questions.

Thanks,
Kyle

I have bought the game but it didn’t let me play it. Because I wanted to play it I then bought the ultimate pass. I own the game however it only works when I have the ultimate pass

No, it won't let me play halo either. I have a valid xbox game pass ultimate subscription though