can't change xbox name on laptop

Hi,

I'm unable to change my Xbox gamertag on my laptop. I get to the stage of conformation, but after I click 'Change gamertag' the popup just goes away and I'm left with the same screen that I had before the popup. I've attempted to change it on multiple devices and it does not work. I don't have access to an Xbox. If I reload the page, it just goes back to the 'inputting username' stage. Can someone please tell me what's wrong and how to fix it? Is it just a glitch?

Thanks

:)