Changed Xbox one to Xbox Series S but some of my games are missing from the library on...

Are they digital or disk games if risk games then no they wouldn't work

Hi, I hope you're doing great out there. I am an Independent advisor and I am here to help you in regard to your concern.

This may mean that these games are not purchased under the account that you're using.

Let's validate, please sign in to https://account.microsoft.com/billing/orders and from there, locate the game order for the games that went missing. The status should be "completed".

If it's not showing from there, it may mean that it's on a different account that you own. Please check all Microsoft accounts that you own.

Got it, yes. I can recommend you the Series S if your library is mostly digital.
Is a great console if you're not looking for the Series X.

If you don't have or aren't interested in 4K on games. That's a good choice

If the Series S isn't a good option for you. Maybe the Xbox One X is the next option. But you're going to miss some next gen games

This did no work as my mother bought the game on her account and we game share , the game was missing on her list too , even after doing the steps the game did not appear on the owned section or gamepass section of the full library on both Xbox series s consoles

UPDATE : I have resolved the situation! While I can't call this a guaranteed solution but I'll just explain what I did.

I used to own a One X. I gave that to my brother over a year ago when I acquired my Series S. I went to his house tonight and played on the One X that I gave him which still had my profile on it. Once I signed in I checked my game library and sure enough, L4D2 was there (whereas on my Series S it didn't show up at all) I installed the game on the One X and booted it up and it worked.

Came home later, unplugged my Series S for a few minutes, plugged it back in and booted it up and lo and behold, there it was in my library!

I'm no genius but my only guess is that some wires got crossed with the license for the game and my profile/consoles. So for all you Series S owners, find a friend or relative that owns an Xbox One and try to install the game on that and then see if it shows up in your Series S library.

I appreciate all the help!