External display. "Out of range" after power saving

I bought a LG 24MP59G-P 24" monitor and connected to my laptop via HDMI.

It works fine. And I'm using a "join displays" configuration, having the new monitor as the primary display.

But after power saving "blank screen", it usually stops working and says: "out of range"

Then I have to switch to text mode terminal (CTRL+ALT+F4) and then go back. Or try to solve it by locking the session, and loging in again. But it takes several tries to get it working back.
And sometimes I've to unplug the HDMI cable, and connect it again.

I wouldn't like to have to be plugging and unplugging the HDMI cable all the time

Is there any configuration that I could use to avoid these "out of range" failures?

Or, as a workaround, could I solve it using command line?
So I could create a script and a key combination to easily restore it

Update:

I tested it using Windows 10 in the same laptop and the problem doesn't reproduce after 20 power savings. So it seems to be an Ubuntu 20.04 bug, a Nvidia driver bug or a misconfiguration

1 Answer

Two possible work arounds:

• xrandr probes display modes and sometimes resets it to a usable one
• xset dpms force off; xset dpms force on will force both monitors off and back on, and sometimes this resets things (or maybe it triggers the problem?)