Hi, I'm using KDE user edition. I've set the taskbar/window list(?) to only show the applications, shown on the specific display (using a multi display setup). When I disconnect the second monitor, the list is not updated and the applications from the disconnected display are not shown in the window list of the still connected display. Even worse, it is completely empty regarding opened applications and opening new applications on the still connected display does not show them in the window list.
Do you mean Task Manager https://drive.google.com/file/d/1qeSzTc0lO0u8TlvWhJxj1jxxVv962K7A/view?usp=drivesdk or Window List https://drive.google.com/file/d/1UWGu0oCLPVjle_ISxm--8siiapDAp-BW/view?usp=drivesdk ?
Ah, it's the task manager, sorry :)
I also have this issue, in Kubuntu 18.04 LTS 64bit, all updates applied. * Nvidia GTX 980Ti, using proprietary driver * Two 4k monitors connected via DisplayPort * The right-hand screen is set as the primary screen (in Plasma settings and in NVidia settings) I've had a lot of multi-display issues with Kubuntu since installing it a few days ago. I initially set it up with a different panel setup on each screen (default panel on left screen, plain panel with just task manager on right). When I turned off my screens and turned them back on (or woke up the screens after they switched off due to the energy saving settings I applied), the panels would be messed up - either the right-screen panel on both, or the left-screen panel on both. I got around this by just having the default panel on both screens, which I can live with, but it's worth mentioning this functionality is not working properly on my setup. I have both task managers to only display the tasks on their screen. After turning screens back on, the right-hand panel lists the tasks for the left-hand screen. I can fix this by turning the right-hand screen off and on again, at which point both screens go black for a few seconds, and then come back with everything fine. (This is definitely not a long term solution though.) Some details: In kscreen-doctor monitor, I see this error when the screens turn off: QXcbConnection: XCB error: 148 (Unknown), sequence: 422, resource id: 0, major code: 140 (Unknown), minor code: 20 QXcbConnection: XCB error: 148 (Unknown), sequence: 424, resource id: 0, major code: 140 (Unknown), minor code: 20 No errors when I turn the right screen off and on to fix the issue. In ~/.local/share/kscreen: $ cat ab40d22f255027ccf68c7cda86e02dc5 [ { "enabled": true, "id": "d915b0a4b961c7f98c1684b5bda3c3c7", "metadata": { "fullname": "xrandr-ASUS PB287Q-127007", "name": "DP-4" }, "mode": { "refresh": 59.99662399291992, "size": { "height": 2160, "width": 3840 } }, "pos": { "x": 0, "y": 0 }, "primary": true, "rotation": 1, "scale": 1 } ] $ cat f5b5d034f6fe6f96d0dc115152858eb9 [ { "enabled": true, "id": "6673f17fb50a7502fe141330288a2b18", "metadata": { "fullname": "xrandr-ASUS PB287Q-41632", "name": "DP-2" }, "mode": { "refresh": 59.99662399291992, "size": { "height": 2160, "width": 3840 } }, "pos": { "x": 3840, "y": 0 }, "primary": true, "rotation": 1, "scale": 1 }, { "enabled": true, "id": "d915b0a4b961c7f98c1684b5bda3c3c7", "metadata": { "fullname": "xrandr-ASUS PB287Q-127007", "name": "DP-4" }, "mode": { "refresh": 59.99662399291992, "size": { "height": 2160, "width": 3840 } }, "pos": { "x": 0, "y": 0 }, "primary": false, "rotation": 1, "scale": 1 } ] $ cat fc7d61093060ac371dc7f0cda8b63971 [ { "enabled": true, "id": "6673f17fb50a7502fe141330288a2b18", "metadata": { "fullname": "xrandr-ASUS PB287Q-41632", "name": "DP-2" }, "mode": { "refresh": 59.99662399291992, "size": { "height": 2160, "width": 3840 } }, "pos": { "x": 3840, "y": 0 }, "primary": true, "rotation": 1, "scale": 1 } ] When my screens are switched back on / woken up, the second file, f5b5d034f6fe6f96d0dc115152858eb9, has its modified date changed (no content change though). After turning the right-hand screen off and on, both the first and second files (ab40d22f255027ccf68c7cda86e02dc5 and f5b5d034f6fe6f96d0dc115152858eb9) have their last modified date changed (no content change).
Forgot to mention, when I apply the workaround of turning right-hand screen off and on, all windows move to the left-hand screen.
I confirm the bug for Manjaro (latest updates), plasmashell version 5.14.3 . My workaround is to restart plasmashell with "killall plasmashell" and running plasmashell thereafter. Do tell if there's any additional info that would be of help.
*** This bug has been marked as a duplicate of bug 394532 ***