Media print and real PDF print have real difference

Context : I’m trying to debug this print :
We understand applying @media print and real print have a lot of difference (paper, orientation etc) but :
The print is working fine with Chrome
The print looks very bad on FF. If we click on landscape : FF add 12k of white pages O_o

We try to debug with the nice media print emulation but the @print is looking great too ^^ but not the real print. We are out of ideas on how debug this case (and other we have to do with same issue).

Thanks if you have some tool/workflow/idea.

Thanks for posting!

I can confirm the issue, I filed a bug on Bugzilla for now Hopefully someone working on print will take a look and advise here.

Whaou ! Very quick support !
I hope for an fix/tip.
If the URL change in the future I will edit the post.