Name not available (even though Lodestone says it is)

I did the name change thing to change my character's name, first looking up on the Lodestone to see if anyone on Excalibur already had it (they don't), and if it was an allowed name (numerous people on other servers with the same name prove it is). But when I actually go in the game to change my name, it says I cannot use it. I can't imagine SE randomly favoring some players over others, so this must be a technical glitch, either in the game that should let me choose the name or on the Lodestone which is not properly displaying all players.

And no I'm not going to say the name because someone with better luck than I will troll me and swipe it under my nose while I'm figuring this out. :(

It may have been added to a list of prohibited names.

Most games have one.

If others have it, that only means they made that character before it was added.