SUMMARY When two windows of the same program are open, and a third window of a different program hides them, clicking on the icons-only task manager to bring one of the windows to the front does not work. When using X instead of Wayland, everything works fine STEPS TO REPRODUCE 1. Launch two Dolphin windows (at this point clicking on the Dolphin icon switches between the two) 2. Launch one window of Konsole (at this point the Konsole window covers the Dolphin windows) 3. Click on the Dolphin icon on the task manager OBSERVED RESULT Nothing happens. Only way to bring Dolphin window up is to hover over the icon EXPECTED RESULT One of the Dolphin windows is brought to the front SOFTWARE/OS VERSIONS (basically used fedora 34 cloud image, and installed the "KDE Plasma Workspace" group with zawertun/kde dnf repo enabled to get latest version) Linux/KDE Plasma: Linux 5.11.18-300.fc34.x86_64 KDE Plasma Version: 5.21.5-3.fc34.x86_64 KDE Frameworks Version: 5.82.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION This initially happend on my laptop when upgrading to Fedora 34, and then was easily reproduced on a (libvirt/qemu) VM. X works fine, this is just Wayland.
Same behavior happens on openSUSE Tumbleweed, also on Wayland only.
Fixed in Plasma 5.22 already. :)