At various times, I have also seen problems printing from Firefox. I'm not sure where the fault is from, but I have a suggestion for a reasonably useful workaround. The key is Firefox's Print Preview function. As a practical matter, that requires that you enable the menu bar in Firefox.
But first, make sure you are keeping Firefox up-to-date. Web browsers frequently have security issues, so make sure yours is kept updated. Updates may also help with bug fixes.
To enable the menu bar, do this _once_:
- 1) Click on the menu symbol (looks to me like a ventilation grille, three or more horizontal line segments. (Depending on your Firefox version, YMMV. I'm using the ESR stream, currently at version 60.3.0esr.)
2) Click on 'Customize'.
3) At the bottom of the browser window, click on 'Toolbars'.
4) Check the box for Menu Bar.
5) Observe a menu bar at the top of the browser window with traditional items: File, Edit, View, ...
Then, to use Print Preview, do this _each_ time you print something when you want to use that function:
- 1) Click on 'File' in the menu bar.
2) Click on 'Print Preview'.
3) Scroll up and down to see an accurate view of what will be printed on each page.
4) If you like, change between Portait and Landscape orientation, change the scale factor, change Page Setup settings, etc.
5) If your browser window is too narrow to show the 'Close' button on the right-hand edge, use Control-W to switch back from Print Preview mode to the original web page.
Hope that helps.
(Edited because I hit the 'Submit' button instead of the 'Preview' button while proofreading.)