When I type @ in Confluence, no user suggestions appear, and my "Disable AutoFormatting" and "Disable AutoComplete" options are unchecked.
@游晓雨 Welcome to the Atlassian Community!
I just got to the stage where I am @ mentioning people in my pages and noticed that I have the same issue.
I have found that it works when I select the @ button on the editor toolbar. I can then select another user from the list presented.
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.