Old gamertag displaying above my new one

Hello, first it's a pleasure to be able to help you today.

My name is welcome to the community.

Hello Charlz, after the Gamertag is changed it can still take more than 72 hours or more to be updated in all Microsoft and developer databases.

So it's normal for your old Gamertag to still appear, but after that it will disappear and only the new one will be displayed.

Hi, I'm , an Independent advisor and I can surely help you.

Don't worry we will work on this together. Just to make sure, did you change your gamertag on your Xbox console?

The double gamertag is by design, as they transition over to the new gamertag system. Not all games will display the new gamertag system and as stated, your old gamertag will be displayed on 360 backwards compatible games. Any gamertag you create yourself,
is a custom gamertag.

Hello, there is no need to contact support. Your son has the correct gamertag, which was changed under the new system. Games still use the old system and will display the old gamertag until 2020. Even then only new games and certain old games will support
the new system. There was an option to change the 'old system' gamertag while you were creating the new one but now it's too late to do it for free.

Thank you! Do you have any idea when the update is?