There's a weird argument that this isn't actually a bug.
If a player needs to modify the title for capitalization or a typo, then they shouldn't necessarily lose out for changing it.
Editors are told that the quiz is a challenge quiz by reading a small red box in the template. Some slip by and some don't; we do try to work to prevent issues like this but some get through.
I personally find it against the spirit of the challenges list to change the title in any way and, when I do see it happen I rate the quiz lower as a result. All of the specifications of the list are spelled out.