This is a known bug related to X-GNOME-Autostart-Phase
in /etc/xdg/autostart/spice-vdagent.desktop
. See bugzilla issue.
So the logical thing is to comment out or delete this line, as comment 13 tried. Apparently it didn’t work for them but it did for me ¯\_(ツ)_/¯.
I’m too lazy to try to understand exactly what it’s doing or why it’s causing issues. It seems like a pretty deep rabbit hole. Well as long as it works I won’t complain.