The signature line shows blank upon printing when I can clearly see the signatures on the document on my screen. Can anyone help please?

Every DS signature is a PDF field, and in my opinion you should look for solution in printing preferences in Acrobat Reader. Try to play with different way of printing (from DS directly via browser printing window, from DS via system printing window, from Acrobat Reader), and check if the results are the same. If not - probably it is the problem of printing options. Acrobat Reader has an option of printing "as a picture" - try it out (Print window >>> Advanced >>> Print as a picture checkbox).

I personally have no idea about the printing issue because I have never ever printed documents signed in DocuSign. Electronic documents should be stored in electronic version. It is the main idea that is behind of all solutions like DocuSign. Save the trees! 😀