if the Italian language is set on the browser from which you access my web space on ITCH.IO, my surname is translated into Fassino;
What?
Are you talking about the language setting in itch or about a language translation feature in the browser? Neither would translate a username. Furthermore, "fassin" translates to ... "fassin".
therefore it turns out that everything I published on ITCH.IO was done by Paolo Fassino and not by me.
The only mention of fassino in association with itch comes from your post here. Your username is part of the url.
You sure you have no bogus addons in your browser? Did you check on a different device, like from your phone? And with different browsers.