SUMMARY
Folder view (icons on desktop) goes further away from top, the more panels exist on top. 
Meaning that 3 short Panels right next to each other on top count, as they would be over each other.
3 Panels with a thickness of 42 Pixels count as 126 Pixels for the folder view while the panels are next to each other.

STEPS TO REPRODUCE
1. Have some icons/shortcuts on your Desktop and put them on the very top.
2. Create a Panel | move to the top, make it to the left and size it smaller.
3. Create another Panel | move to the top, make it to the middle and size it smaller.


OBSERVED RESULT
2. Notice how the Icon moves below the panel with the right distance (Normal behavior)
3. Notice how the Icon moves further away from the panel, double the distance (Not normal)

EXPECTED RESULT
Icons should be right below the thickest panel.


SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux 6.1.1-zen1-1-zen (64-bit)
(available in About System)
KDE Plasma Version: 5.26.4
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.7