SUMMARY
I have 2 monitors.
When my plasma panel is on left monitor on X11 session and i start wayland session, my plasma panel appears on right monitor.
Same happens with my desktop settings like wallpaper and desktop icons.
Monitor arrangement is correct on both Wayland and X11

STEPS TO REPRODUCE
1. Start X11 session
2. Make one monitor have plasma panel and desktop icons, make sure another monitor does not have plasma panel and has different background image.
3. Start Wayland session and observe, that desktops are swapped in places

OBSERVED RESULT
Desktops are swapped
Sometimes, when i start X11 session, my plasmashell arrangement is swapped like on wayland, but it swaps back in 1 or 2 seconds.

EXPECTED RESULT
Desktops are not swapped

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.21.90
KDE Frameworks Version: 5.82.0
Qt Version: 5.15.2+kde+r196-1, last updated 2021-05-26
Kernel Version: 5.12.9-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz
Memory: 15.5 GiB of RAM
Graphics Processor: Mesa DRI Intel® HD Graphics 4600

ADDITIONAL INFORMATION