We have machines running SDDM, the KDE/Plasma display manager. One user prefers Gnome as her desktop environment. There is no problem selecting that session when logging in. The screen however never turns off and goes to power save mode when the session is inactive. Apparently, the Gnome desktop environment requires GDM for full functionality.
Previously she started
gnome-screensaver manually after logging in, but that program has been deprecated for a while, and is no longer part of the distribution. We have tried some other screensavers, but they seem to have problems, perhaps because they are made for the X11 environment and not working properly with Wayland. Xscreensaver for example starts drawing its saver screens, but does so even when the user is active! It never seems to enter the power save mode.
Does anyone know a solution for this? Is it possible to have the screen deactivated during inactivity when running a Gnome session but using SDDM as display manager? In our use case the actual locking isn’t important, but the power save mode of the monitor is.