FlyingSaucer 9.1.13 wrong absolute position div rendering

[Viktor Remennik]

G'day,

Just found this great lib and made a simple app to test it. Unfortunately, I can't understand, am I doing something wrong, or it is a bug.

Here's a simple html I am trying to convert: https://base.elsi-a.com/_generated.html

I put a "ruler" line at the a4 right 210 mm margin to understand the box position. As you can see, box is aligned at the right page side, and fits inside the page:

Exactly the same I see when I try to print it from the browser:

But in the PDF converted by FC I see this box moved to the right, out of the page boundaries!

I tried to use xr.layout.bad-sizing-hack = true but with no success. Is it possible to make the div box positioning right?

Please help.