Unsetting the GTK_IM_MODULE environment variable makes the problem go away.
Possibly related: bug #1765304. ** Changed in: firefox (Ubuntu) Importance: Undecided => Medium ** Changed in: firefox (Ubuntu) Status: New => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1803631 Title: Clicking an <input type="password"> field in a webextension popup will cause popup to close To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/firefox/+bug/1803631/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs