KDE plasma graphical bugs

Hey all, having a weird issue.

It’s been a while maybe since the last time I ran an update on my machine, so of course, that meant it broke something. This time, its plasma.

I dont know how to describe the issue I’m having so I’m linking a screenshot.

I’ve tried uninstalling plasma, along with erasing the cache and config files, so I should be back to an absolute, out of the box plasma.

even the add widgets menu goes off the screen.

EDIT: in the screenshot the widgets menu isnt off the screen and my panel isn’t weird, but on my end I assure you it is!

specs
OS: Arch Linux x86_64 
Kernel: 5.4.65-1-lts 
uptime: 3 hours, 19 mins 
Packages: 1871 (pacman), 6 (snap) 
Shell: fish 3.1.2 
Resolution: 2560x1440, 1280x1024, 2048x1152 
DE: Plasma 5.19.5 
WM: KWin 
WM Theme: Layan-solid 
Theme: [Plasma], Layan-dark-solid [GTK2/3] 
Icons: [Plasma], breeze [GTK2/3] 
Terminal: terminator 
CPU: AMD Ryzen Threadripper 2950X (32) @ 3.500GHz 
GPU: AMD ATI Radeon RX Vega 56/64 
GPU: NVIDIA GeForce GTX 1080 Ti 
Memory: 7686MiB / 64180MiB

I had the same issue once when I added a new monitor, KDE was apparently weirded out by the new total resolution. IIRC I deleted ~/.config/plasmashellrc and re-applied the new Display Configuration manually and it fixed it.

Just tried that, unfortunately, no luck. It fixed it for the session, but if I log out then back in I have it broken again.

Hey, so I tried degrading my KDE installation one version, to no avail. Also another thing to note is that KRunner and notifications keep popping up in the middle of the screen instead of where they’re supposed to be. Anyone have any ideas?

I suspect it will result in the same behavior but it can be a good test if not tried:

  1. One quick test to be sure it’s not related to any other config files or overlooked state in your home directory is to create a brand new user and test logging in twice. (also being aware of if it’s an issue with Wayland or Xorg/X11 session and any differences might offer insight/workaround)

The fact that it works on first login after removing the config is interesting, possibly the auto config is ok but what it wrote out or the reload of it later is odd.

  1. It may be worth collecting the xrandr output in the “just logged in after removing the file” and the bad states. (It is usually for X11 but may give some output for wayland as well.) The intention is to see if the two monitors are overlapping coordinates for some reason; or if the maximum viewport looks too small for the total resolution for some reason. (if randr output looks odd, we might be able to run commands to get it fixed temporarily using xrandr/arandr etc, and if so to launch something on session login as a quick hack, but knowing if that works or looks odd can help moving forward)

One other test (with xorg) might be to boot / switch to runlevel 3 (text / multiuser mode):

  1. using init 3 or similar, then try startx if you have it or xinit to see if a session comes up and if that is working. Just in case the graphical display manager is doing something odd prior to login, though I’m not sure I’d at first suspect that. (runlevel 3 will exit any existing session/applications; and graphical mode can be returned by init 5 or rebooting if needed; changing runlevel usually requires sudo/root)

And you may have tried another desktop environment already, but:

  1. testing a similar desktop environment might help judge if it may be KDE specific. (I’m not sure if that was clarified yet.)

Otherwise if it’s Xorg then checking the /var/log/Xorg.0.log or journalctl logs after the issue has occurred (for X11, looking for ‘EE’ or ‘WW’ though sometimes lines with that on them are not fatal/concerning Errors or Warnings. It may also show the resolutions it’s detecting and switching between (comparing working and non working) in those logs.

  1. Are Nvidia/other proprietary graphics drivers being used on the system?

  2. Being sure all package updates have happened and nothing is holding part of them back, can help if there is any strange incompatibility between KDE and other supporting packages; but this may already have been tried.

I’m unsure that I have quick answers for debian based system rollbacks as I’m unfortunately focused on rpm based distros myself, otherwise I might try to offer help

I apologize, as beyond the new user and trying Xorg/Wayland for any difference/improvement, the others may require a bit more data and investigation unless the issue can be found already discussed online. Also, after some initial checks, if it may be KDE specific and known by others then it may be worth checking with ubuntu forums or kde if worth the time.)

Thank you for the tips! I can use gnome just fine, I just prefer KDE. So it is KDE specific. I’m using AMD graphics (proprietary and otherwise for drivers), the nvidia is for my VFIO passthrough.

I’ll try looking at my logs and other tips in a bit

I should also mention that the session works for the most part. I can use it as okay enough and the window management and compositing etc still works. It’s just that Krunner, the wallpaper, notifications, and some misc windows I use often will pop up where the shouldn’t. Krunner and my notifications pop up in the middle of the screen, where it used to be out of the way. Also, I’m not running on Debian or ubuntu, I’m on Arch

I’ve not tried out the proprietary AMD driver in a while and don’t have a modern AMD card at the moment (just older HD3850). So I’m not certain I know of any options or known behaviors for it (regarding RandR/Xinerama and similar).

Oh, I may have been a bit too tired when I had posted, or am just now learning to read the tags on the posts. And the expandable specs section. :slight_smile: (On there are three monitors for KDE!? or is that third one in the spec list for the nvidia pass-through one) Sorry I totally missed that “>specs” expand box in the original comment.


In that case, for the startx/xinit from runlevel 3 part of my past comments then this might be relevant https://wiki.archlinux.org/index.php/KDE#From_the_console
(I’m not sure that this will show any behavior difference if it’s already using Xorg in the session and seeing the same issues; unless there is a chance that the login greeter is leading to some issues.)

Regarding the xrandr output, I’m wondering about what comes out if you just run xrandr by itself in a graphical terminal.

  • An example of output is in the beginning of this section:
    https://wiki.archlinux.org/index.php/Xrandr#Testing_configuration
    where we can see the total size and also the WxH+x+y and some other details for each display (if it’s not showing as a single one).

  • We would also want to compare it’s output when it works after removal of the configuration file previously noted, and then after re-logging in and seeing the problem state. It’s ok to just collect the problem state output if logged in at the moment (and not wanting to logout yet).

  • Since I’m not sure of all the separate files kde might keep details (like locations of widgets etc in addition to resolution etc), it may still be worth testing as a newly created user to confirm the behavior (I’m not sure if just moving the .kde directory(s) from various places covers everything).


I’m not sure if you’ve had a chance to check the the output of running xrandr in a graphical terminal but it may help to provide that here and maybe a photo of the monitor(s) and screenshot of the same state to compare. (Possibly with one window straddling across the two monitors; and then maybe one moved as far to the left as possible, into the area that can’t be seen if it does not stop at the edge of the widget (not sure if ‘cut off’ is partially or fully cut off).


  1. Ah, so you don’t happen to see duplicated windows when dragged around the screen in certain areas, where their content is possibly duplicated in the area where the wallpaper is duplicated on the same screen (either when over top of the normal-ish sized wallpaper on the left or over the other one? I guess by the compositing/management comment that it’s drawing windows in places without any issues. Do you see the black area above the shrunken and duplicated wallpaper (seen in the left monitor side of the screenshot)? (Or is that actually a middle monitor and does anything show up on that monitor, and maybe only part of it?)

  2. Out of curiosity, does putting them in an arrangement of “above and below” instead of “right and left (side by side)” lead to any better behavior (just for testing purposes)? (or if it’s 3 monitors for kde then stacked top to bottom or having one of them below and two side by side) That will be a pain for using until pop up notifications occur to confirm etc, but the wallpaper antd widgets/bars behavior may show right away.

I’m slightly concerned about if the distance between the two displays within the viewport space is wide and leading to issues (but am not quite sure about what you see vs the screenshot or in comparison to any xrandr output).

  1. Does the mouse take a while to pass between the monitors (from one edge to the other, as if there was space between them) or does it show up on the other monitor as soon as it drops off the other?)

The way its described makes it sound like it is zoomed like overscan like on a tv where it crops the image, but the fact that the wallpapers are calculated/displayed oddly I’d guess would not support overscan as the only issue. Though I’m not sure from the screenshot vs what is seen on the monitors. (Any chance we could get a photo and screenshot for the time the photo is taken? just to be sure about what is seen)