Board Thread:Support Requests - Getting Technical/@comment-38501248-20200525150821/@comment-9605025-20200525191533

Templates appearing multiple times in the editor's list is a known bug with UCP wikis. Fandom should be working on a fix though we have not actually had confirmation of this.

As for dealing with the two separate templates, you could have also just changed Template:Character into a redirect. Just replace the content with: This way, if a user used Template:Character, they would actually be using Template:Character_Infobox.
 * 1) REDIRECT Template:Character_Infobox

Although, this information doesn't really help now since you already went though and fixed everything another way.