The newer versions of Firefox use an internal PDF viewer rather than that from Adobe (who owns Acrobat and the PDF standard) and some users have reported problems with printing, such as
- Incorrect page sizing/fitting
- buttons and other page elements overlayed on printed PDFs
To remedy this you can try the following:
- Go to Firefox > Options
- Go to Applications tab
- Search PDF and the from Actions dropdown menu select the "Use Adobe Acrobat" option
If this does not remedy your issue please try using an alternative browser.