Why is my new gamertag under my old onel?

Typically if you use things like special character, your old tag will remain to be in use in areas that haven't been updated to use the new gamertag rules.

Hello Ray, My name is David. I am an independent advisor, happy to help you today.

I'm sorry that you are having problems with your Xbox Gamertag, remember that;
On Xbox 360 gamertags can be up to 15 characters, including spaces. They cannot start with a number.

On Xbox One, Xbox Series X|S, and Windows: Gamertags can be up to 12 characters, including spaces. They cannot start with a number.

Xbox gamertag changing rules may mean that certain special characters or formats do not update correctly in all areas of the system. In some cases, the old gamertag may appear temporarily until the information is fully updated across all Xbox Live servers and systems.

My suggestion would be to wait a little longer, to see if the problem is resolved, for example, 24 hours

We can also try to log out and log in again to your account in the console and check if the name was updated, but normally this is more of a system problem.

However, below I will leave you a link in which you will have access to the official article in which Microsoft explains how to update the Gamertag
https://support.xbox.com/help/account-profile/profile/gamertag-update-faq

Best regards.

Hi, for some reason my old gamertag is showing on the xbox app, yet I changed my gamertag ages ago. Is there any reason why my old gamertag is showing on the xbox app rather than my new gamertag?

Try signing out and then signing back in.

Hi Rodrigo. I still have access to the account under my new primary. It defaulted to my new primary when I deleted the email that used to control my account. My gamertag and lifetime worth of gaming is under the email I removed from the account before making the new one my primary, so my Xbox profile is no longer under my account since I deleted the old one early if that makes sense. Is there any way to get my old Xbox live account back?

ok thank you for your message, the odd thing is when i did change my other account his gamertag it did work normal.

no other gamertag under it..

it only happend with this one, thats why i found it a bit strange.

When i login on the xbox website with this gamertag what i changed it shows me the old gt still, but on my second account where i also changed the gamertag, when i login it shows up with the new gamertag.

regards

Xbox is currently changing the Gamertag system.

During that transition period, you might see your old gamertag as well as your new one.

Current and older games that don't know of the new Gamertag system will still show your old Gamertag. And it can take until 2020 until the full transition to the new Gamertag system works in all games.

So currently what you see is not an error. It's just how Gamertags are handled during this transition to the new Gamertag system.