Disable GDM Auto Suspend
Create /etc/dconf/profile/gdm:
sudo nano /etc/dconf/profile/gdm
With the following content:
user-db:user
system-db:gdm
file-db:/usr/share/gdm/greeter-dconf-defaults
Save and exit. Then, create /etc/dconf/db/gdm.d/:
sudo mkdir /etc/dconf/db/gdm.d
Create /etc/dconf/db/gdm.d/99-disable-suspend:
sudo nano /etc/dconf/db/gdm.d/99-disable-suspend
With the following content:
[org/gnome/settings-daemon/plugins/power]
sleep-inactive-ac-type='nothing'
sleep-inactive-ac-timeout=0
TipThe config above would work with AC power. For it to work when on battery, add the following:
sleep-inactive-battery-type='nothing' sleep-inactive-battery-timeout=0
Save and exit. To apply the changes:
sudo dconf update
sudo reboot
References
https://wiki.archlinux.org/title/GDM#GDM_auto-suspend_(GNOME_3.28)
https://unix.stackexchange.com/questions/361214/disable-gdm-suspend-on-lock-screen/746767#746767