Cant change in game name

Yeh i did one of those super surveys and received enough zp to change my name. So i after i bought it i went into my items and pressed use and enterted the name i wanted into the New call name bar.
however when i try to write that same name in the confirm new call name bar i get this error:

please input correct new name


ive checked and the name that i want is available so i dont understand what the problem is. when i press use nothing happens.