Why are some of my previously purchased games not showing up?!?

Back when I had an xbox 360 I had bought or downloaded thru game pass, gta 5 and multiple other games digitally, I now have an xbox x, I've logged in with the same account and gta 5 along with a few other games like farming simulator, fallout 4 and 3, and a few other are not showing up as owned games, why is that??!?

:)