Links that point within the document or the ones pointing out to an external link?

When I export a doc as a pdf, the internal links are preserved when I open them in preview. In the PDF.js I click on the print icon and then click PDF > Print as pdf then hit print and the external links are preserved.

Can you please clarify what steps you are taking exactly to print/create the doc and clarify what kind of link?

Note :This sounds like a bug, but cannot reproduce it. Need exact steps/

Thanks for taking care! Here the pcocedure: Investopedia site, I go to an article, I press the print icon top right, the print window opens, i press the pdf button, 'save as pdf', then when I open the pdf saved file with Preview (the same with Adobe reader) and I try to open an external link to another Investopedia article within the pdf file (text in blue) nothing happens (and the blue text doesn't contain any link anymore). When I do all this procedure with Safari it works.

Sounds that you use a PDF printer driver that creates a text link instead of a clickable (active) link.

But the printer driver is the same used by Safari and with Safari the links are preserved...