Can't post URLs with CJK chars in them?

Hey, Im trying to share a post from マリウス.com, but clicking the submit button just returns an error that the link is not a valid URL. Ive also tried percent encoding to %E3%83%9E%E3%83%AA%E3%82%A6%E3%82%B9.com, with the same results. I assume this is not intentional @Deimos?

EDIT: It looks like punycoding it to xn--gckvb8fzb.com works.