Firefox "Save to PDF" function does not print headers/footers

Firefox 125.0.2 does not print anything in the headers and footers when I try to save a webpage using the Save to PDF function. For example, I configure the Page Setup to only show the URL on the top left, then go to Print... , choose Save to PDF , and tick Print headers and footers . The headers/footers in the previewed page are empty. Similarly, if I go to about:config and change the print.printer_* settings before printing, the headers/footers are also empty: What am I doing wrong? (I prefer to use Save to PDF rather than Microsoft Print to PDF because the latter will sometimes save the web

Question by Medulla Oblongata on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.