For years I was experiencing problems with my printing. On many web pages (eg Consumer Reports) a banner was inserted at the top of the print page (printer and pdf) that blocked some of the text of the page. Also many blank pages were inserted at the end of the document. I don't know what I did exactly but the problem suddenly disappeared. What I did in frustration was to go to the about:config and filter to print. I didn't see anything that I would dare try to change. I isolated the modified choices. Well the bottom line was that when I tried to print a bad output the printing was perfect. I think the controls were in the about:config but they were never picked up or registered but I could be entirely wrong. I don't think I changed anything when I was in there. Before I did that I also tried to use Google Chrome. That one gave me a good print page also. Opera did not. Now Opera was working also. I am using Linux Mint 19.3. I just hope my computer doesn't have a relapse.