I want to ensure that no one else can use my Gamepass

I see, I recommend resetting the Microsoft Store to see if the problem persists:

Type wsreset in the Windows Search box, right click the first result and select "Run as Administrator"

After some time, the Microsoft Store will re-open.

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

If your account is signed into the Microsoft Store, any account signed into the Xbox app can access the installed game. The only way to prevent this would be by changing the Microsoft Store account as well as the Xbox app account.

Please reach back if you have further questions.

Thanks,
Kyle

Hello Kyle,

I have checked by completely logging out from MS store as well. Even after doing that, any Xbox App login can access and play the game. Any other ideas you may suggest pls.

Thanks,

your dad has ultimate, you get access to gamepass games on console, but thats not how it works on pc, your dad is the only one that can use gamepass on pc, nobody else.

Yes everyone else has answered the question, but the other option is if they sign up to gamepass i believe its the same version as came with the xbox one S package as I have that and also the gamepass one installed on my X so the two boys can play together