Signing in with new account

Hit Xbox Buttton, with LB to arrive the tab with your photo and name (The last on the left). There will find "add new" to add a new account, after you add if you need to logout or change profiles you have the options in the same tab: "Logout" and "Change
Profile". See if you can find it

Sign in with a new account, or sign up for a new Microsoft account.

I am unable to attempt to add a new account or sign into a new account. I can sign into accounts already on my Xbox

I was able to successfully sign in with the new account on the Xbox website. I tried the power cycling and removing the new account and adding it back and that still doesnt work. The new account is able to sign on the Xbox, but when I try to sign in for
the split screen or try to sign that account into the game itself it just says that the profile/account could not be downloaded.

I tried that.

Created a new windows user account but I can't sign in the new account.

It's asking for my password then it shows my account and "sign in" underneath.

I click on sign in but nothing happens.

And after a minute the whole system restarts to sign in again with my main account.