Site works best with Chrome. Though just ran it with IE 11 and worked fine with the reply thing.
May be a bug with the browser. Not sure. I faced some other issue with Mozilla Firefox, where if I try to add a link, it simply adds the link with an "underline" and doesn't let me edit its description.
I guess Firefox bug.
Unless you try to do something beyond what you have already mastered, you will never grow!