Comment 22 for bug 1971434

Can confirm #18 - same results here.

The only solution I have found so far is to run a script via crontab.
Check to see if monitor should be off "xset -q" looking for "Monitor is off"

If it is supposed to be off call
"xset dpms force suspend
sleep 2
xset dpms force off
"

This seems to get the monitors into standby mode - just forcing the off did not work for me - ymmv

This is an inelegant hack but it now means the monitors spend more time asleep than on which is progress.

This definitely isn't gnome-settings-daemon related but perhaps I wrongly assumed gnome-screensaver was what handled display sleep - this won't get the attention it needs here though.