Note that I've tried upstream's tarball for a few weeks and couldn't reproduce the issue with it.
So either the bug is specific to Debian or it has disappeared (or I haven't tried long enough). I'm now trying with Debian's package firefox 100.0-1. -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)