SUMMARY Suppose you have a panel in the left of the screen and some plasmoids on the desktop. Then, after each restart of Plasma, the widgets will move a bit left. After many restarts, they will move steadily to the left edge of the screen. STEPS TO REPRODUCE 1. Place panel to the left 2. Place some plasmoids on desktop 3. Restart Plasma many times OBSERVED RESULT The widgets move left on each restart EXPECTED RESULT The widgets remain on the same position as before the restart SOFTWARE/OS VERSIONS Linux/KDE Plasma: (available in About System) KDE Plasma Version: 5.26.90 KDE Frameworks Version: 5.102.0 Qt Version: 5.15.8 ADDITIONAL INFORMATION See also https://bugs.kde.org/show_bug.cgi?id=458038#c19.
The bug is present only after updating to 5.26.90. Before that, the widgets might move to the left sometimes, but it happened at most one and whey didn't move anymore.
Fixed in the final Plasma 5.27 release.