Yes, if you’re seeing something that says “this user has not filled out their profile page yet” it means the account is unregistered, so I’m not sure why it says the username is taken. Try again, and if still says the username is taken, you can contact staff and ask them to help. It might be a glitch

What is the username you wanted? When Fandom checks if a username is available, it checks not only the exact username you provide but for similar usernames. This is to prevent people from impersonating others. For example, if someone already has the username "IAmTheBest", you probably won't be able to register similar usernames such as "lAmTheBest" (lowercase L instead of uppercase i), "iamthebest", or "IAmtheBest".

Yeah, sorry, I didn't realize that it said the same for both. I meant something like this: