While we appreciate this is effectively a functional regression, it is intended. Exposing firefox's menus to the global menu bar involved a non-trivial distro patch that was increasingly difficult to maintain (because it relied on many internal APIs), so it was dropped before 20.04 (see https://bazaar.launchpad.net/~mozillateam/firefox/firefox.focal/revision/1340).
The firefox updates in 16.04 and 18.04 still carry the patch, FWIW. ** Changed in: firefox (Ubuntu) Status: New => Won't Fix -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1890049 Title: global menu bar no longer supported after 20.04 upgrade To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1890049/+subscriptions -- ubuntu-bugs mailing list firstname.lastname@example.org https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs