Created attachment 152231 [details]
Issue present on a screenshot

SUMMARY
I run two displays, 1080p internal and 1440p external, external is being driven by Nvidia, as verified by gpu not idling in nvidia-settings.
If I set same resolution for both displays, changing screen layouts proceeds smoothly with no glitches, howerver if external runs at higher resolution and I switch to external only, I get wallpaper corruption.

STEPS TO REPRODUCE
1. Set higher resolution on secondary screen.
2.  Switch between internal only, extended, and finally to external only, just to make sure that more than one wallpaper is cached.
3. In external only mode two wallpapers are present, main on the left, and a piece of second on the right.
4. Clicking on desktop makes main wallpaper span whole desktop, switching to some application brings the glitch back, clicking back and forth fixes it eventually.

OBSERVED RESULT
Two wallpapers are present on a single screen

EXPECTED RESULT
Only one wallpaper should be present when only one screen is being driven.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.6
Kernel Version: 5.19.9-zen1-1-zen (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 4800H with Radeon Graphics
Memory: 15.0 GiB of RAM
Graphics Processor: AMD RENOIR
Manufacturer: LENOVO
Product Name: 82B1
System Version: Lenovo Legion 5 15ARH05H