Comment 16 for bug 1975884

I have the same symptoms on 3 different computers (all upgraded from Ubuntu 20.04).

I do have the error message "Removing a network device that was not added" in /var/log/syslog, but not at the time when the problem occurs.

My computers are always plugged to the network with an ethernet cable.

I only have one gnome extension (on the 3 of them): https://github.com/paradoxxxzero/gnome-shell-system-monitor-applet

I found the workaround to hit ctrl-alt-F1 then ctrl-alt-F2: after typing my password again, my session is back