Comment 47 for bug 1971434

This is Gnome bug I presume that manifests mostly on Ubuntu (clash with Canonical's tweaks) with some HDMI monitors (mostly Lenovo). The same monitors work as intended under Windows.

My bet is they send some message back to the computer when they change power state after requested to go to full power save. That in exchange wakes up the system, which ten keeps the screen blank, but backlight don't go off; they don't go off on both screens. If I turn off my Lenovo with switch, the laptop screen finally turns off after some time, but not always.