Bug 509930 - When switching from multi-screen arrangement back to one screen, panel popups that were open on now-disconnected screen move to current screen
Summary: When switching from multi-screen arrangement back to one screen, panel popups...
Status: RESOLVED FIXED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Panel (other bugs)
Version First Reported In: 6.3.4
Platform: Kubuntu Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords: multiscreen
Depends on:
Blocks:
 
Reported: 2025-09-25 13:37 UTC by Franco Pellegrini
Modified: 2025-10-03 16:09 UTC (History)
4 users (show)

See Also:
Latest Commit:
Version Fixed/Implemented In: 6.5.0
Sentry Crash Report:


Attachments
Screenshot on how notifications show up with 3 monitors (3.67 MB, image/png)
2025-09-25 13:38 UTC, Franco Pellegrini
Details
Screenshot what happens after unplugging the dock (1.72 MB, image/png)
2025-09-25 13:39 UTC, Franco Pellegrini
Details

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Description Franco Pellegrini 2025-09-25 13:37:17 UTC
SUMMARY

I have a multi monitor setup at home using a dock, with 2 external monitors. I have it configured so each monitor has its own panel, and they mostly are duplicates, with the only difference that the "Task Manager" widget is configured to only show apps from that screen, and I have pinned apps that I expect to open in that particular screen.

The issue I am observing is, when the dock is plugged in, and I have 1 or 2 external monitors, the notification widget (If a notification comes in) will pop up on all 3 monitors and this is fine and expected (Although, maybe it would be nice if it is configurable and so it can be set to only come up for the screen that has the focus right now, but that's a separate thing.)
Anyway... The issue I am seeing is that when I unplug the dock from the laptop, and everything comes back to the only primary screen, I am observing multiple notifications popping up.

I suspect that there is no proper cleanup happening when disconnecting the external monitors and all widgets from the external monitors continue to run... although I am only able to see the notification widget because it pops up, unsure how to check how many running widgets there are... is there some sort of "ps" command I can run to get the running widgets?


STEPS TO REPRODUCE
1. Boot up KDE in laptop, single screen
2. Plug a device so notification pops up
3. Observe 1 notification
4. Plug dock with 1 or 2 external monitors, each configured with its own Panel and notification widget
5. Plug a device so notification pops up
6. Notification pops up in all screens
7. Unplug dock
8. Plug a device so notification pops up
9. Observe 2 notification widgets popping up

OBSERVED RESULT

More than 1 notification widget pops up when coming back from multiple monitors connected, to a single laptop screen

EXPECTED RESULT

Only 1 notification widget should popup, as it happens before plugging in the external monitors.


SOFTWARE/OS VERSIONS
Windows: 
macOS: 
(available in the Info Center app, or by running `kinfo` in a terminal window)
Linux/KDE Plasma: Kubuntu 25.04
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.3
Graphics Platform: Wayland
Kernel: 6.14.0-29-generic (64-bit)

ADDITIONAL INFORMATION

I am not sure if this could be related to https://bugs.kde.org/show_bug.cgi?id=496006 in my case, the laptop screen is always the primary display, whether the dock is plugged in or not.
Comment 1 Franco Pellegrini 2025-09-25 13:38:18 UTC
Created attachment 185256 [details]
Screenshot on how notifications show up with 3 monitors
Comment 2 Franco Pellegrini 2025-09-25 13:39:04 UTC
Created attachment 185257 [details]
Screenshot what happens after unplugging the dock
Comment 3 Marco Martin 2025-09-26 14:41:40 UTC
can't seem to reproduce on master, with a similar panel on 2 screens, if i disconnect the other i then get only one popup
even if both popups were open when i disconnected the screen
Comment 4 Nate Graham 2025-10-03 16:09:18 UTC
I have the hardware to almost perfectly replicate this setup, but I can't reproduce the issue in current git master either.

Let's assume at this point that it's been fixed for Plasma 6.5. However Franco, if you still experience it after you upgrade to Plasma 6.5, please do feel free to re-open this bug report.