I am forced to manually type in "-Atcovi (Talk - Contribs) 18:34, 19 December 2016 (UTC)", which is quite unfortunate. Please change this.
Topic on 2017 wikitext editor/Feedback
What about ~~~~, if you don't like the button?
Well, he might have used that; if you don't remember to nowiki the code, then it gets converted when you save. There is more information and ideas about how to address this at phab:T153255
Atcovi, how have you normally added your signature in the past?
By pressing a button which automatically pasted ~~~~ And whoops my bad on the first post.
They looked into this a while ago, and most people don't use the signature button. However, I suppose that new editors might use it more. Also, different languages have different keyboards, and these punctuation keys aren't always in the same place.
Atcovi, if you prefer, then you can go to Insert > More > Your signature. But I think that most editors will find it faster to type four tildes instead.