Once you've done that, please let me know and we'll copy your inaccessible CMDR over to this account while we continue our investigation. Once we've sorted things out we'll then move your back.
Ok, it makes more sense now. As you share more clues, it starts to become more obvious what they want to do.
Per this reddit thread, it seems that 1 Elite Dangerous install on an Xbox can be used by any gamertag on the xbox:
Reddit post on multiple gamertags using 1 ED account
So what I'm seeing in your responses is that your main gamertag is messed up in ED, and they don't know why. So their suggestion is to make a new gamertag on the XBox, load up ED and log in using the same email as your existing frontier account. This
should, I think, open ED on your existing Frontier account. No more steps required.
Then they want you to make a new commander with a name, and then let them know when you are done. They will grab your current commander on your main gamertag, and MOVE him to replace the new commander you just made on the new gamertag. That will be temporary, so that you can play Elite Dangerous while they figure out what happened to your main account. Eventually, they will move him back.
In theory, you will log into ED using the new gamertag and it will act like you've never logged into ED before, even though it's still the same frontier account. If I read correctly, that appears to be a feature of XBox allowing "game sharing" between gamertags on the same XBox.