firefox does not see printer

[Jan Stary]

This is current/amd64 with firefox-68.0.2

Firefox does not offer any prtinters in the printing dialogue
except (Print to file").

lpd/lpr itself works fine. This is my /etc/printcap:
lp:lp=:rm=147.32.232.36:rp=lp:sd=/var/spool/output/lpd:lf=/var/log/lpd-errs:
Each of "date | lpr" and "lpr file.pdf" works.

I removed the entire ~/.mozilla directory fo make sure
it is not some of my firefox settings.

Is this known?
Is a fix known?

        Jan