My gamertag is still the same although it said yesterday that I was able to successfully...

For reference:
GT-A = old gamertag
GT-B = new gamertag

Hello,

I tried to change my gamertag from GT-A to GT-B. Yesterday, after my first try, it said I was able to successfully change my gamertag to "GT-B". But currently, my profile is still "GT-A" for some reason. And what's weirder is that when I try to search "GT-B" in the Find people or clubs search bar, I can see one user with that name (probably me? because I'm assuming it bugged out after changing my gamertag). I'm 100% sure there was NO user with "GT-B" as gamertag before I attempted to change mine. And now, whenever I try to change it again to GT-B, it won't let me have it anymore. It now suggests me variations (e.g., GT-B4562). I'm clueless what is happening. I'm aware that I may have to pay in order to change my gamertag but there was no option for that. I'd gladly pay to change my gamertag, but I think Xbox is having issues with gamertags at the moment? Not sure what's going on. Any help would be much appreciated. Thank you so much!

:)