This has been annoying me for some time and I want to try and fix it.
I'm running Zorin 17.3 on an Asus mini-PC. The PC is connected to a Samsung monitor via HDMI, and the monitor is shared with a Mac Mini. When I switch inputs away from the Asus (on HDMI2) to the Mac Mini (on HDMI1), it works fine. When I try to switch back to the Asus, I get a blank screen. Nothing works to trigger a response. I have to pull the power cable on the Asus and plug it back in again to get any video.
Settings -> About says "llvmpipe (LLVM 15.0.7, 256 bits)"
Does Your System run in Wayland or X11? You can check that with the Terminal Command echo $XDG_SESSION_TYPE
Should it run in Waylan, I would suggest to switch to Xorg. to do that, go to the Login Screen. Click there on Your Profile so that the Password Field appears. When it is appeared, You should see a Gear Icon in the bottom right Corner. Click on it and choose the Option ''Zorin Desktop on Xorg'' and then log in and test it.
When Your posted Output is complete, You seem to have an Intel Graphics, maybe integrated Graphics Unit in the CPU. When You go to the ''Additional Drivers'' Tab in Software & Updates are there any Nvidia Drivers offered?
I did, yes, and it does appear to be integrated Intel drivers so I was wrong in my assumption. Apologies. The PC spec states Intel® UHD Graphics (N97).
An additional data point. I had to add nomodeset to grub as Zorin was constantly failing to show any video during boot unless I went into recovery mode and booted from there. However that shouldn't affect video behaviour once the OS has fully booted and it has switched to its own drivers.
I can try some newer drivers if I knew which ones.
No luck, unfortunately. I had to revert that change as it stopped any video from appearing after the OS had loaded after selecting "Zorin" from Grub.
It seems to me that the OS is detecting a lack of signal from the monitor and disables video, but it fails to detect when the monitor signal resumes. It could be the cable, but I've swapped cables and no difference. It may be the monitor itself but the Mac mini happily restores video when I switch the input back to it.
I'll see if I can source another monitor but this one is a very recent Samsung 32" (model U32J59x) so it ought to work. I note that Zorin doesn't seem able to detect the monitor model whereas macOS does. I wonder if that might be relevant?