SUMMARY
I have 2 monitor setup. One monitor positioned horizontally (1920x1080) and another vertically (1080x1920).
When I have window, e.g. system settings but this isn't really important what window it is, spawned on the vertical screen with width taking full width of monitor (1080), when I move it to the horizontal screen it's automatically resized to full width too (1920). This behavior seems odd for me as usually, when window was full width on the vertical screen I don't want to have it full width on the horizontal screen (which is much wider).


STEPS TO REPRODUCE
1. Run e.g. system settings on the screen with width 1080 - it needs to use full width of screen but not full height,
2. Move the window with mouse to the other screen with with 1920 - it will be automatically resized to take full width of the new screen automatically when You drop it with mouse.

OBSERVED RESULT
Window resized to much wider screen automatically

EXPECTED RESULT
Window which wasn't on full screen, should remain with same size after moving it to the other screen

SOFTWARE/OS VERSIONS
Operating System: Arch Linux
KDE Plasma Version: 5.23.1
KDE Frameworks Version: 5.87.0
Qt Version: 5.15.2
Kernel Version: 5.14.13-arch1-1 (64-bit)
Graphics Platform: X11
Processors: 12 × Intel® Core™ i7-9850H CPU @ 2.60GHz
Memory: 62,5 GiB of RAM
Graphics Processor: Mesa Intel® UHD Graphics 630