Settings -> Power -> Blank Screen set to 1 minute
Ubuntu 20.04, fresh install. Dual monitors, one connected via HDMI, the other via DVI. After a minute, both monitors slowly fade to black. Then one monitor goes into standby. When the other monitor goes into standby, the first one powers back up and then the other powers up. Both screen remains black, though, with only their backlighting and the mouse pointer visible.
$ xrandr -q
Screen 0: minimum 320 x 200, current 3600 x 1080, maximum 16384 x 16384
HDMI-A-0 connected 1680x1050+1920+0 (normal left inverted right x axis y axis) 474mm x 296mm
1680x1050 59.95*+
HDMI-A-1 connected primary 1920x1080+0+0 (normal left inverted right x axis y axis) 521mm x 293mm
1920x1080 60.00*+ 50.00 59.94
DisplayPort-0 disconnected (normal left inverted right x axis y axis)
$ xset q
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 0 cycle: 0
DPMS (Energy Star):
Standby: 0 Suspend: 0 Off: 0
DPMS is Enabled
Monitor is On
It looks like this may be an ongoing issue with multi monitor setups. A review of some of the relevant questions:
proposes a workaround solution to disable the auto input select option on the monitor. My HDMI monitor does not contain such an option to disable, so sadly this is a no-go.
suggests using setterm on an Ubuntu Server installation. This command returned an error. I suspect it isn't relevant to desktop installations.
involved using xset dpms force standby. I also tried xset dpms force off. Both results were the same: both monitors would go black, then one would power down and when the other powered down, they would both power back up. With both commands, the screens were visible rather than remaining black.
suggested dpkg-reconfigure gdm3 which had no visible effects on my installation.
Any thoughts or insights would be most appreciated!
EDIT: The issue still exists after a fresh install of 21.10.
