That microsoft account doesn't exist

Im having a separate problem where whenever i load up or close down a game itll sign me out, and to fix this i need to delete the account and clear the cache. Afterwards, i need to re download the profile, but to do that i need to know if i can, otherwise
ill have lost a profile with money put into it.

Did you try using a phone number that might be tied up to your account? Because you might be using a different email to that account before. It will not change the email to that account if you do not have access to the primary email before and most especially the security proofs.

Had the same issue contact support and waste a hour and they will fix it apparently its a server bug that they are trying to fix

Also, when I click "use another device" on my series X and put in the code it gives me on my phone that's logged into the same account it doesn't do anything...

I'm logged into Microsoft.com and the Xbox app on my phone but my Xbox still says account doesn't exist... ****?