Bug 475487

SUMMARY
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I have 3 displays x 4 activities, each configured with a uniquely different wallpaper (that's a total of 12 wallpaper configurations) and often when resuming from standby usually at least one or two activity display wallpaper settings reverts to the theme default.

It is also worth noting this occurs after booting-up and logging in for the first time as well.

I have also noticed that `~/.config/plasma-org.kde.plasma.desktop-appletsrc` is modified to reflect the wallpaper reversions as if some (disaster recovery?) code determined that it was necessary to revert the wallpaper settings for those activity displays (but not the others).
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STEPS TO REPRODUCE
1. Configure four activities on three displays
2. Set a unique wallpaper for each screen on each activity
3. Put the system into standby
4. Resume from standby

OBSERVED RESULT
At least one or two wallpapers revert to the theme default, seemingly at random.

EXPECTED RESULT
Wallpaper configuration remains intact


SOFTWARE/OS VERSIONS
Operating System: Kubuntu 22.04
KDE Plasma Version: 5.24.7
KDE Frameworks Version: 5.92.0
Qt Version: 5.15.3
Kernel Version: 6.2.0-34-generic (64-bit)
Graphics Platform: X11
Processors: 32 × 13th Gen Intel® Core™ i9-13900K
Memory: 125.6 GiB of RAM
Graphics Processor: NVIDIA GeForce RTX 3090/PCIe/SSE2
NVidia Driver: 535 (CUDA)

ADDITIONAL INFORMATION
It is also worth noting that there are numerous other glitches (perhaps associated with lost GPU surfaces from resuming from standby that applications do not restore) after resuming from standby that causes Discord to crash, window decorations to fail as fixed images (buttons do not render any depress graphics when clicked) that scale erratically when the window is resized, and I am required to consistently restart `kwin_x11` with `--replace` each and every time resuming from standby to avoid further rendering issues.