I have a destkop with 7 folder views, three icons, and two panels (right and bottom). Every time I log in about half the folder views are in a slightly different location (sometimes slightly resized as well) and all of the icons have move slightly. Those that are effected are the ones that are closest to the panels on the bottom and the right. The two folder views closest to the upper left corner of the screen never move or change size. My guess is that the folder views and icons are being laid out on the screen before the panels have been displayed and then their position and size is being moved once the panels start taking up space (both of them are thicker than the KDE default so they change the available real estate to a significant degree). Some of the folder views and icons are placed fairly close to the panels, but none of them overlap, so there shouldn't be any need to move or resize them.
Are you on X11 or Wayland? If it's X11, this is Bug 458038.
I am on X11, so this does seem like a duplicate of https://bugs.kde.org/show_bug.cgi?id=458038 I apologize for not finding it when I searched before filing the bug report. *** This bug has been marked as a duplicate of bug 458038 ***
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This is fixed for me with the current packages in Debian testing.