I have two screens, and the task manager on each screen is filtered to only show tasks from that screen. After the screens switch off, either manually or automatically due to power saving, when the screens come back on, the task manager on the right-hand screen shows the tasks for the left-hand screen. Also, all tasks have moved to the left-hand screen. I've found two workarounds to cope with this for the time being: 1. Switch the right-hand screen off and on. Both screens will then go blank for a few seconds, then the right-hand task manager is fixed. 2. Kill and restart plasma-shell. I should mention other multi-monitor bugs I've found workarounds for but might be related. I originally tried setting up a different panel setup on each screen, but after the screens switched off and on the panels would be messed up - both screens would have the same panel, or one panel would go missing. I eventually just set up the same panel on both screens, and had to reapply this multiple times until it was stable. I suspect the way Plasma detects what each screen is, or maps the panel config to each screen, gets confused when the screens switch off and on, and this could be related to the panel bug. I've also had serious trouble getting the wallpaper and desktop-icon config on my screens to stay correct. SETUP * Kubuntu 18.04, all updates as of 21-MAY-2018 * Nvidia GTX 980Ti, using proprietary driver nvidia-driver-390 (390.48) * Two 4k monitors connected via DisplayPort * The right-hand screen is set as the primary screen (in Plasma settings and in NVidia settings) 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).
This seems to be "fixed" if I make the left-hand monitor the primary screen. The right-hand task manager now lists the correct tasks after screens are switched back on, and continues working without needing to restart plasma-shell. However, the windows are all still moved to the left-hand monitor.
I've discovered it's only maximised windows that get moved to the left screen.
In Plasma 5.13.5 the central bug of this ticket still occurs: The window list of one screen will sometimes list the windows for the other screen after the screens come back on after powersaving. Right now, it's the left screen task manager listing the windows for the right screen. Restarting plasma shell is the only way to fix this. I'm using an AMD Vega 64 card with the default built-in mesa drivers, on KDE Neon 5.13 - based on Bionic. The rest of my system is the same as it was. The other bugs I've reported here are not present, either they were fixed in Plasma recently or they don't occur on AMD cards. $ inxi -Fxz System: Host: ****** Kernel: 4.15.0-34-generic x86_64 bits: 64 gcc: 7.3.0 Desktop: KDE Plasma 5.13.5 (Qt 5.11.1) Distro: KDE neon User Edition 5.13 Machine: Device: desktop Mobo: MSI model: X99S SLI PLUS (MS-7885) v: 1.0 serial: N/A UEFI: American Megatrends v: 1.E0 date: 06/15/2018 CPU: 6 core Intel Core i7-5820K (-MT-MCP-) arch: Haswell rev.2 cache: 15360 KB flags: (lm nx sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx) bmips: 39598 clock speeds: max: 3600 MHz 1: 1200 MHz 2: 1259 MHz 3: 1779 MHz 4: 1199 MHz 5: 1279 MHz 6: 1200 MHz 7: 1200 MHz 8: 1232 MHz 9: 2328 MHz 10: 1200 MHz 11: 1204 MHz 12: 1200 MHz Graphics: Card: Advanced Micro Devices [AMD/ATI] Vega [Radeon RX Vega] bus-ID: 05:00.0 Display Server: x11 (X.Org 1.19.6 ) drivers: ati,amdgpu (unloaded: modesetting,fbdev,vesa,radeon) Resolution: 3840x2160@60.00hz, 3840x2160@60.00hz OpenGL: renderer: Radeon RX Vega (VEGA10 / DRM 3.23.0 / 4.15.0-34-generic, LLVM 6.0.0) version: 4.5 Mesa 18.0.5 Direct Render: Yes Audio: Card-1 Advanced Micro Devices [AMD/ATI] Device aaf8 driver: snd_hda_intel bus-ID: 05:00.1 Card-2 Intel C610/X99 series HD Audio Controller driver: snd_hda_intel bus-ID: 00:1b.0 Sound: Advanced Linux Sound Architecture v: k4.15.0-34-generic Network: Card: Intel Ethernet Connection (2) I218-V driver: e1000e v: 3.2.6-k port: f020 bus-ID: 00:19.0 IF: eno1 state: up speed: 1000 Mbps duplex: full mac: <filter> Drives: HDD Total Size: 500.1GB (19.1% used) ID-1: /dev/sda model: Samsung_SSD_840 size: 500.1GB Partition: ID-1: / size: 457G used: 90G (21%) fs: ext4 dev: /dev/sda2 RAID: No RAID devices: /proc/mdstat, md_mod kernel module present Info: Processes: 272 Uptime: 2 days Memory: 3254.6/11905.9MB Init: systemd runlevel: 5 Gcc sys: N/A Client: Shell (bash 4.4.191) inxi: 2.3.56
The bug is still present in KDE 5.17.3, right now the lastest version.
Same problem on KDE 17.08 with Plasma 5.18.3, workaround also is swap Task Manager plasmoids manually using mouse drag in edit mode, but this helps until next restart :(
*** Bug 397626 has been marked as a duplicate of this bug. ***
*** Bug 387901 has been marked as a duplicate of this bug. ***
*** Bug 391033 has been marked as a duplicate of this bug. ***