Note : this behaviour usually starts to occur after a couple of days uptime (this is on a Dell XPS7390 2-in-1 with unrecognized fingerprint reader), for every action which requires authentication (su, sudo, virt- manager, screensaver unlocking).
journalctl error message (for the "su" example from comment#20) : Aug 22 10:50:12 mymachine su[2571952]: pam_fprintd(su:auth): GetDevices failed: Connection timed out -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-shell in Ubuntu. https://bugs.launchpad.net/bugs/1824855 Title: Unlocking the screen takes a long time after "Starting Fingerprint Authentication Daemon..." To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fprintd/+bug/1824855/+subscriptions -- desktop-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
