Even Wordpress' interface is broken. When you update a user and you click the link to return to the search result at the top you're taken to a link with the @ symbol removed.
I opened a bug report a long time ago but they seem to care more about making it difficult for us to ask for help than actually replicating the problem and fixing it when aware of issues.
Wordpress did NOT have this problem before. It started with an update released shortly before my original topic there.
Can anybody help and maybe join the conversation over there, so hopefully one of the developers maintaining Wordpress actually looks into it? Maybe they think I am a single lunatic with the issue and won't bother helping if they don't see others asking for help too.