Old and New gamertag showing on same account

Hi. No it isn't showing both at the same time. When I turn on xbox it shows my new gamertag. But whenever I go online it shows the old one. Playing mw3. Multilayer with my friends they are still seeing the old gamertag. When I log in to Microsoft online it shows my new gamertag.

I've cleared cache on the xbox. Deleted profile and added again and still not updating.

I changed my gamertag 2 days ago and it's doing the same thing. on Xbox live friends list and in party chat it shows my old gamertag and on the Xbox app. On xboxlive.com it shows new gamertag

Yes it shows my old account that i use to have no one is using it and its the same gamertag.

Didnt helped unfortunately

Anyone?

Me either it actually made it worse, my old gamertag that I paid for is showing up still and it shows for all of my friends on friends list. And when I look at my account it says my old gamertag then my new gamertag below it but smaller.

You actually show as having a classic gamertag and a new gamertag. So some areas will still show the old gamertag (classic gamertag).