lbesso I think the issue is due to an unsupported feature in an older version of Safari. Unfortunately, I can't fix it right now without rewriting a major portion of the code base. Can you please ask the student to use Chrome and see if that fixes the issue?
(I would suggest updating Safari, but that usually requires updating the entire computer's OS. While recommended, this would take a while to do. I would recommend your students update their computers regularly.)