When printing, not all items in PDF are printing

So when I print to PDF, from CAD, everything is showing when I few the PDF. When I go to plot it on my plotter, or small printer, there are items that don't print.

For instance, we insert a digital signature on our plan, then create a PDF of the plan to send to the client. On the PDF, the signature is showing, but if we print it, the signature is missing.

This is not the digitally sign feature, this is an image that has been inserted into a CAD file, then printed as a PDF, then trying to print the pdf.