[DESKTOP] Disappearing wallpapers

[horizn]

Firstly I found this after upgrade from 20.04 to 22.04. I bought a new hard drive and installed 22.04 from scratch but the problem persist. I found other people having the same issue developing bash and python scripts which is an absolute joke. Do anyone know what is causing this?

[claydoh]

Do anyone know what is causing this?

No, unfortunately. I know that various Plasma devs have been looking at this. There may be multiple causes here, where something is messing with the plasma-org.kde.plasma.desktop-appletsrc file, among other causes.

I have wallpaper oddities myself. The thing is, it is not terribly consistent and repeatable for me.

[jlittle]

Does the problem affect wallpaper plugins? I adopted Vallpaper years ago to get different wallpaper for different desktops. It can do slideshows and even video, though I've only dabbled with that. There used to be a live feed from the ISS one could use, for example.

[claydoh]

It seems somewhat random (in my case) , and not related to the plugin used. Something is messing with plasma-org.kde.plasma.desktop-appletsrc and/or crashing plasmashell. The former resets wallpaper settings back to stock, the latter gets a black screen.
And I am sure that kscreen2 is involved. Of course it is
Multi-monitor setups seem to be the most common systems that see this, but it is not exclusive, trawling through bugs.kde,org. And there seems to have been a large bump (launch ramp/brick wall) of this sort of thing since Plasma 5.25 or so, so relatively recent in KDE in general.
I think that whatever method being used to identify monitors/screens is easily confused, considering that though I have identical models, each has a different serial reported. But they have completely different configuration info between wayland and xorg sessions, in terms of layouts, wallpapers, etc.

For me, it only seems to happen when my monitors power off. Not sleep, hibernation, or locking - I don't use those at home. Some times, at some point after the screens have shut off, and when they come back on, one of my monitors (right) is black. If i simply restart plasmashell, the left monitor reverts to stock Plasma wallpaper, and the Right goes to unique wallpaper I had set it to. usually a slideshow. But it doesn't matter if I have the same wallpaper on each screen, or even go back to X11 (so it def is not a Wayland issue)
But it is not common or repeatable, at least for me.

So, a very simple script I set up to stop plasmashell, replace the config with a known good copy, and restart plasmashell, works when needed. Though manually fixing is only a few clicks, really.