when i try to create an account it won't let me choose a gamertag

I'm having a similiar issue, I was trying to change my gamertag to a different Microsoft Account , only to find that account had a gamertag (although I don't ever remember creating one for that account) So I created a new account to switch that out, only
it won't let me swap the account, I get to 6, and won't let get to step 7

I'm having this same problem. I know for a fact that I would've changed my gamertag when I created my account if I could, since I tried to and it wouldn't let me. I don't know why it won't let me change it for free.

The suffix is added when you choose a gamertag that is already taken. In order to have a gamertag without the suffix, you would need to choose a gamertag that no one else has.

What about 12 characters or less? My gamertag is more than 12 characters. My gamertag is like catgir trucki. Im afraid that i won't create my xbox live account with my lovely gamertag that is the same gamertag from my old xbox live account that have been
delete or banned.

Well, my old gamertag had a space, and it won't let me have any variation of it, but when i try to get my old gamertag with no space in between, it lets me have it...

You can't put your gamertag on another account. If you choose to give it up on account 1 and then try changing account 2 to that gamertag there is no guarantee that it will be available right away or that you won't have numbers put after it. That's the risk you take when giving up an old one.