Is it a problem with edX? Certificates don’t fit perfectly on the paper whatever configurations you choose. It doesn’t look professional in my opinion. How can it be fixed?
I had a similar problem with some users, but it seems to have been sorted out when I told them to try changing their BROWSER’s print option’s size to A4 or to US Letter. They went quiet, which may indicate that this was the solution. Or maybe not. Perhaps someone else can offer better clarity?