And yes this username doesn't finalize post saving the ignore/block list.
The system removes all duplicate names. I you pasted a name into the field and then did same in the find member option, both usernames will be entered on the list, but when you click to save, only one of the duplicate username will be displayed.
A fix for you will be to use the ignore option without the find member list since you know who you want to ignore.
- Jay -