Pc game pass gamertag not changing

If you're doing it from the website, change the region in the far bottom left corner of the page. It likes to default to the US for some reason.

on the game pass app and the pc itself which account are you signed into?

also if you play on console and have changed your gamertag recently to a new one it may give you a different new one for games that cant host the new gamertag format

Ultimate is just a bundled subscription of Gold, Game Pass for console, and Game Pass for PC. It doesn't change what games are available on Game Pass. Doom Eternal is available with Game Pass for PC.

Sorry but I'm afraid that the Game Pass can only be shared on the Xbox. On the PC only the gamertag that purchased the pass can use it

Game Pass Ultimate is only a bundled subscription of Gold, Game Pass for console, and Game Pass for PC. It doesn't change what games are available on each platform. Game Pass for PC doesn't have the same amount of games as Game Pass for console, so you won't see all of the same games on the PC.