Going to https://beta.musicbrainz.org/user/Vaylon shows the attached for me. I'm ''guessing'' that it's related to the missing "last login", which means this is likely only an issue if 1) the editor is an old account and they didn't log in since we started tracking "last login" (which I'm not sure of when that was), and 2) if the user viewing the editor is an account administrator (otherwise the "last login" is not displayed at all to begin with).