Bug 509930

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.