SUMMARY
Using two monitors with different sizes. Randomly (I haven't been able to replicate manually), the desktop background in the bigger monitor will change to the one with smaller resolution. I've uploaded images with the issue, and how it normally looks.


STEPS TO REPRODUCE
Can't seem to replicate it manually, don't know which logs to look for.

OBSERVED RESULT
Background image (or the whole desktop background, really) changes at random. 

EXPECTED RESULT
Background image size shouldn't change

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch, up to date
(available in About System)
KDE Plasma Version: 5.27.7
KDE Frameworks Version: 5.108.0
Qt Version: 5.15.10

ADDITIONAL INFORMATION