gnome-session maybe useing wrong way to suspend.
Ubuntu 20.10, gnome 3.38.3, I am using multi-seat via loginctl. When ever a seat is idle for some time system suspend this is not a desired behavior. I quote https://github.com/systemd/systemd/issues/18054
Also see there is no suspend button on power-setting.
Also note when a other seat user logout the seat0 also logout. To know more about multiseat read https://www.freedesktop.org/wiki/Software/systemd/multiseat/
Edited by Bapi Dey