zhetengtiao are you using an extension to enable usernames like these? Because Flarum doesn't natively support them. The usernames are constrained by a regular expression and our internal testing only covers those username formats.
We have the Nickname extension, but I don't think it allows the Nickname to be used as part of the URL without a custom extension being developed.
PS: we have now introduced ID-based profile page driver in core which can help for situations where the username isn't publicly shown and the nickname isn't suitable for URL.
