Probably related to bug https://bugs.kde.org/show_bug.cgi?id=369130 I have a setup with two monitors operating in different resolutions, one of them is in vertical mode (rotate left). Most of the times , when I return to my session after it got locked because of inactivity, the taskbar that was placed on screen one, is suddenly on screen two. I'm going to add some more info as soon as I can find some pattern. Reproducible: Sometimes Steps to Reproduce: 1. lock your session 2. unlock your session 3. Actual Results: Taskbar moves from the rightern monitor to the leftern Expected Results: Taskbar should stay. The rightern taskbar is attached to the bottom. The leftern taskbar on the vertical monitor is attached to the top.
multi monitor management changed completely in 5.8. please reopen if this is still reproduciblr in Plasma 5.8 or newer.