SUMMARY When setting which activity a window should appear in via the Task Manager, the window will no longer change which activity it is on anymore. The only thing that does change is that the icon for the window appears on the selected activity but when it is clicked the activity switcher returns the user to the activity where the window originally opened in. STEPS TO REPRODUCE 1. Open a program/window 2. Right click the program/window icon in the Task Manager and assign a new activity via "Show in Activities" 3. Switch to that activity and notice that the program/window is not present OBSERVED RESULT Window continues to only appear in the activity it was launched in. EXPECTED RESULT Window should appear in all activities that are selected for it under the "Show in Activities" menu as it originally did before this bug. SOFTWARE/OS VERSIONS KDE Plasma Version: 5.23.2 KDE Frameworks Version: 5.87.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION If a user right clicks the title bar of a window and assigns the activities using the "Show in Activities" menu then the window appears in all of the selected activities. This may indicate that this is an issue with the Task Manager instead of the activity manager. Other users have reported having this issue on Reddit: https://www.reddit.com/r/kde/comments/o7gdaa/show_in_activity_all_activities_for_a_window_has/
I also have this problem, and more information. If I click 'Show in Activities' > 'All Activities', it does work if it shows a radio button for 'All Activities'. If it shows a checkbox for 'All Activities', it does not work. Right-click on window title bar: 'All Activities' is radio button, and change works Right-click on taskbar icon: 'All Activities' is checkbox, and change does not work One window I want on all activities does not have a title bar, so workaround to right-click on title bar does not work for me. I also see the behavior on Reddit thread where clicking on the application icon/widget in the task manager takes me to the activity where the window was launched. I use Kubuntu 21.10.
This was fixed a while back and I can confirm that it's working now in Plasma 5.27.4.