Can't suspend machine anymore?
$ systemd-inhibit
WHO UID USER PID COMM WHAT WHY MODE
NetworkManager 0 root 2045 NetworkManager sleep NetworkManager needs to turn off networks delay
Realtime Kit 0 root 2391 rtkit-daemon sleep Demote realtime scheduling and stop canary. delay
UPower 0 root 2588 upowerd sleep Pause device polling delay
GNOME Shell 674777 vorburger 5801 gnome-shell sleep GNOME needs to lock the screen delay
GNOME Shell 674777 vorburger 5801 gnome-shell sleep GNOME needs to save screen time data delay
vorburger 674777 vorburger 6064 gsd-media-keys handle-power-key:handle-suspend-key:handle-hibernate-key GNOME handling keypresses block
vorburger 674777 vorburger 6064 gsd-media-keys sleep GNOME handling keypresses delay
vorburger 674777 vorburger 6065 gsd-power sleep GNOME needs to lock the screen delay
vorburger 674777 vorburger 5790 gnome-session-s sleep user session inhibited block
$ gnome-session-inhibit -l
No inhibitors
$ gsettings get org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type
'nothing'
$ gsettings set org.gnome.settings-daemon.plugins.power sleep-inactive-ac-type 'suspend'
Suspend works again.