How do I keep hyperlinks active after signing a pdf?

We have exported a PDF from procore (our project management software), and saved this file to our server.  This file contains hyperlinks to documents within procore.  When we open the file in Adobe Standard XI these hyperlinks work.  Then we place a signature on the file and save it.  NOTE:  When just clicking "save" it pops up a window like "save as" typically does, it does not just save the file.  Once this save is completed, the hyperlinks are no longer active.  How do we sign the document, but keep all hyperlinks active?