I print part of the page with blocks (screen print dialog from Chrome): 
In Mozilla, when printing, the display of pictures changes every time: then there are none of them (instead of them there is an empty space with alt), there are several pictures, the rest are not. You can print two times in a row and get a different display. For example, here is (screen print to PDF from Mozilla, the same on paper): 
Reprint a few seconds after updating the page: 
Reprint a few seconds after updating the page: 
But after updating via Ctrl + F5, the pictures disappear, and everything is new. It seems that the browser gradually loads images as the page is updated, and then after several updates it prints normally.
Chrome prints fine, grabs the first time. All blocks are made by copy-paste, pictures are also the same from the same source made and processed in the same way.
And sometimes even not gradually loaded.
