If it's not saving the name you want then it's because Bungie's filters are blocking whatever you're attempting to use. I recommend trying another name.
Note: If you're using the FireFox web browser, disable any extensions you have, as these can cause issues.
English
-
It looks like the name is already registered and cannot be changed again. I have replaced it once in the past, but it was over a year ago. Is it not possible to change Bungie ID a second time? Also, I'm not an English-speaking person and can't speak English, so I use a translation site. I'm sorry if I said something strange due to a translation mistake.
-
Bungie names do not have to be unique.