Bug 510865 - KDE Plasma second monitor does not display wallpaper or context menu
Summary: KDE Plasma second monitor does not display wallpaper or context menu
Status: REOPENED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Activities in general (other bugs)
Version First Reported In: 6.3.0
Platform: EndeavourOS Linux
: NOR grave
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2025-10-21 12:37 UTC by matospmiguela
Modified: 2025-12-26 23:17 UTC (History)
2 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments
Notice that the second monitor is black, and when you try to right-click, there is no response. (391.58 KB, image/png)
2025-10-21 12:37 UTC, matospmiguela
Details
kscreen debub report for black screen issue (7.48 KB, text/plain)
2025-12-26 21:40 UTC, Allen
Details

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Description matospmiguela 2025-10-21 12:37:38 UTC
Created attachment 185965 [details]
Notice that the second monitor is black, and when you try to right-click, there is no response.

SUMMARY


STEPS TO REPRODUCE
1. Log in with your username.
2. Perform your regular activities.
3. Disable sleep/hibernation mode.
4. Turn off the monitors in use and leave them idle.
5. Return the next day and enter your username password.
6. Check that the wallpaper is missing on the second monitor and that the context menu is not working.

OBSERVED RESULT
Notice that the second monitor is black, and when you try to right-click, there is no response.

EXPECTED RESULT
Display both wallpapers, or one if you have set them to replicate on both monitors.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: EndeavourOS
KDE Plasma Version: 6.4.5
KDE Frameworks Version: 6.19.0
Qt Version: 6.10.0
Graphics Platform: X11

ADDITIONAL INFORMATION
Attached is one of the latest screenshots I took showing the problem described. Note that this has been happening since Plasma 6.3, and I haven't been able to find a solution, and this bug has not yet been reported.
Comment 1 Bug Janitor Service 2025-10-21 13:33:40 UTC
Thank you for the bug report!

However Plasma 6.3.0 no longer receives updates or maintenance from KDE; active versions are 6.4 or newer. Please upgrade to an active version as soon as your distribution makes it available to you. Plasma is a fast-moving project, and bugs in one version are often fixed in the next one.

If you need help with Plasma 6.3.0, please contact your distribution, who bears the responsibility of providing help for older releases that are no longer receiving updates from KDE.

If you can reproduce the issue after upgrading to an active version, feel free to re-open this bug report.
Comment 2 matospmiguela 2025-10-27 12:18:21 UTC
I can confirm that after updating the operating system, and with version 6.5 just released, when I log in again the next day, the problem recurs.
Comment 3 matospmiguela 2025-10-27 12:19:46 UTC
(In reply to matospmiguela from comment #2)
> I can confirm that after updating the operating system, and with version 6.5
> just released, when I log in again the next day, the problem recurs.
Comment 4 Allen 2025-12-26 21:40:17 UTC
Created attachment 188005 [details]
kscreen debub report for black screen issue

I have attached a full kscreen-console report.  I've confirmed the issue is resolved entirely by disabling Kscreen 2 (kcm_kded) which strongly suggests a timing conflict during the initial handshake of the two ports.
Comment 5 Allen 2025-12-26 21:51:02 UTC
Comment on attachment 188005 [details]
kscreen debub report for black screen issue

Software:
KDE Plasma Version 6.5.3, 
KDE Frameworks Version 6.20.0, 
Qt Version 6.10.1, 
Kernel Version 6.14.0-37-generic (64-bit) 
Graphics platform Wayland

Hardware:
Processors - 4 x Intel Core i5-6400 2.7Ghz
Mem - 8GiB
Graphics Processor - Intel HD Graphics 530 "integrated" 
Manufacturer - AsusTek 

Monitors:
Primary  - DVI - Acer  Model R240HY  
Secondary - HDMI - Dell ST2421LB
Comment 6 Allen 2025-12-26 22:36:37 UTC
With Kscreen 2 disabled the desktop now initializes correctly on both monitors Acer (DP-1) and Dell (HDMI). 

there is approx a 10 second delay (latency)  after desktop initialization before the desktop shell (right click functionality) became active.  this suggests that the system is successfully waiting for the DVI handshake to complete where as KScreen 2 was likely timing out and failing during this window.   Again KDE Neon Plasma 6.5.3.
Comment 7 Allen 2025-12-26 23:17:39 UTC
I also observed that before disabling KScreen 2 the Application Launcher (kickoff) would not close when clicking away; it required a second click on the icon to dismiss.  Since disabling KScreen 2 service, the launcher now correctly auto-hides when losing focus.   This suggests the handshake latency was impacting the global window focus chain. 

*hope this helps