Clarification: the issue is only present when the external display is connected.

Created attachment 185846 [details]
Video of window flickering

In the video, the window flickering is the KDE Wallet Service pop-up
"KDE has requested to open the wallet..." and the password input
The content of the window within the borders flickers between the text that should be there and the wallpaper behind it

This seems different than the other bugs mentioned that might be related.
Bug 494156 the entire window geometry is flickering
Bug 509429 the opacity of the window flickers, but doesn't obscure the text with other desktop elements
Bug 504016 has black areas appear over the wallpaper, widgets are unaffected

I'm not able to reproduce this in Plasma built from git-master, using the Wallet Manager window on the laptop's primary display, external monitor connected, and following the steps to reproduce. I have a few questions to try to narrow things down so we can reproduce this.

I notice that you're using an NVIDIA GPU. Are you using the open or proprietary drivers?
What do you have enabled in Settings - Desktop Effects?
Also, can you reproduce this with other windows / applications?


Thanks!

Also, can you please attach your ~/.config/kwinrc file? Thanks!

(In reply to TraceyC from comment #3)
> This seems different than the other bugs mentioned that might be related.
> Bug 494156 the entire window geometry is flickering
> Bug 509429 the opacity of the window flickers, but doesn't obscure the text
> with other desktop elements
> Bug 504016 has black areas appear over the wallpaper, widgets are unaffected

You may be right. I included the links for due diligence and because I also had symptoms like these. That is, the exact flickering behavior was not always identical to the video I included. At one point, I thought it only occurred when positioning the window over widgets, but this turned out to be incorrect. In retrospect, I should have described each of the variations.

> I'm not able to reproduce this in Plasma built from git-master, using the
> Wallet Manager window on the laptop's primary display, external monitor
> connected, and following the steps to reproduce. I have a few questions to
> try to narrow things down so we can reproduce this.
> 

I am no longer experiencing the issue, still on the same system now with the following changes from the initial report.

Operating System: openSUSE Tumbleweed 20251228
KDE Plasma Version: 6.5.4
KDE Frameworks Version: 6.21.0
Qt Version: 6.10.1
Kernel Version: 6.18.2-1-default (64-bit)

I believe it took a few weeks for the problem to disappear. Apparently, I got used to dealing with the flickering and failed to notice and report exactly when it went away. I'll answer your questions in case this is still useful now or in future.

> I notice that you're using an NVIDIA GPU. Are you using the open or
> proprietary drivers?
> What do you have enabled in Settings - Desktop Effects?
> Also, can you reproduce this with other windows / applications?

* Proprietary NVIDIA drivers. As I recall, I also tried the proprietary Intel driver (with NVIDIA disabled) as a workaround and had the same symptoms.
* Desktop effects
  * Track Mouse
  * Blur
  * Desaturate Unresponsive Applications
  * Highlight Screene Edges and Hot Corners
  * Thumbnail Aside
  * Wobbly Windows
  * Dialog Parent
  * Dim Screen for Administrator Mode
  * Overview
* Yes, I could reproduce the issue with other windows and applications. I don't think I found any reliable exceptions. Flickering seemed to affect any active window on the primary display after switching to another virtual desktop. I remember that PDF-Xchange running under wine was affected -- probably a bad example. Firefox from the Tumbleweed repo was also affected. KDE wallet was an example that I tested to check if KDE applications were affected in addition to wine and gnome.

The issue can be closed if resolution on my system is all you need.

(In reply to TraceyC from comment #4)
> Also, can you please attach your ~/.config/kwinrc file? Thanks!

[$Version]
update_info=kwin.upd:replace-scalein-with-scale,kwin.upd:port-minimizeanimation-effect-to-js,kwin.upd:port-scale-effect-to-js,kwin.upd:port-dimscreen-effect-to-js,kwin.upd:auto-bordersize,kwin.upd:animation-speed,kwin.upd:desktop-grid-click-behavior,kwin.upd:no-swap-encourage,kwin.upd:make-translucency-effect-disabled-by-default,kwin.upd:remove-flip-switch-effect,kwin.upd:remove-cover-switch-effect,kwin.upd:remove-cubeslide-effect,kwin.upd:remove-xrender-backend,kwin.upd:enable-scale-effect-by-default,kwin.upd:overview-group-plugin-id,kwin.upd:animation-speed-cleanup,kwin.upd:replace-cascaded-zerocornered

[Compositing]
LatencyPolicy=Low

[Desktops]
Id_1=desktop1
Id_2=desktop2
Id_3=desktop3
Id_4=desktop4
Id_5=desktop5
Id_6=desktop6
Id_7=desktop7
Id_8=desktop8
Id_9=desktop9
Name_1=NW
Name_2=N
Name_3=NE
Name_4=W
Name_5=C
Name_6=E
Name_7=SW
Name_8=S
Name_9=SE
Number=9
Rows=3

[Effect-desktopgrid]
BorderActivate=3,5
TouchBorderActivate=2

[Effect-mousemark]
Color=255,128,255
LineWidth=6

[Effect-overview]
BorderActivate=9
TouchBorderActivate=4

[Effect-windowview]
BorderActivateAll=3,5

[ElectricBorders]
TopLeft=ActivityManager

[Input]
TabletMode=off

[MouseBindings]
CommandActiveTitlebar2=Shade
CommandInactiveTitlebar2=Shade

[NightColor]
Active=true
NightTemperature=5700

[Plugins]
blurEnabled=true
desktopchangeosdEnabled=true
fadingpopupsEnabled=false
fullscreenEnabled=false
kwin4_effect_eyeonscreenEnabled=true
kwin4_effect_morphingpopupsEnabled=false
kwin4_effect_scaleEnabled=false
kwin4_effect_windowapertureEnabled=false
magiclampEnabled=true
shakecursorEnabled=true
squashEnabled=false
thumbnailasideEnabled=true
trackmouseEnabled=true
translucencyEnabled=true
wobblywindowsEnabled=true
zoomEnabled=false

[ScreenEdges]
RemainActiveOnFullscreen=true

[Script-desktopchangeosd]
PopupHideDelay=500

[TabBox]
SwitchingMode=1

[Tiling]
padding=4

[Tiling][desktop3][5b154f0f-f62a-4fce-a263-49503762a0c1]
tiles={"layoutDirection":"horizontal","tiles":[{"width":0.25},{"width":0.5},{"width":0.25}]}

[Tiling][desktop3][5f0b7c9c-3df7-4dfd-9009-bdf18c7632be]
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[Tiling][desktop3][60acde4e-f6fa-47e5-b92b-ad49d2551dc6]
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[Tiling][desktop3][9d8d271e-3437-43d3-8bd6-669be75ef905]
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[Tiling][desktop3][cfbf3694-57a9-485c-9522-ac9bdefe8e79]
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[Tiling][desktop3][d7331781-2985-408d-ada2-e4ee97583b35]
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[Tiling][desktop2][5b154f0f-f62a-4fce-a263-49503762a0c1]
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[Tiling][desktop2][5f0b7c9c-3df7-4dfd-9009-bdf18c7632be]
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[Tiling][desktop2][60acde4e-f6fa-47e5-b92b-ad49d2551dc6]
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[Tiling][desktop2][9d8d271e-3437-43d3-8bd6-669be75ef905]
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[Tiling][desktop2][cfbf3694-57a9-485c-9522-ac9bdefe8e79]
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[Tiling][desktop2][d7331781-2985-408d-ada2-e4ee97583b35]
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[Tiling][desktop1][5b154f0f-f62a-4fce-a263-49503762a0c1]
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[Tiling][desktop1][5f0b7c9c-3df7-4dfd-9009-bdf18c7632be]
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[Tiling][desktop1][60acde4e-f6fa-47e5-b92b-ad49d2551dc6]
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[Tiling][desktop1][9d8d271e-3437-43d3-8bd6-669be75ef905]
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[Tiling][desktop1][cfbf3694-57a9-485c-9522-ac9bdefe8e79]
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[Tiling][desktop1][d7331781-2985-408d-ada2-e4ee97583b35]
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[Tiling][1d5ac860-bf1c-52fc-b781-922683364f6c]
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[Tiling][23fa60ca-91bc-5b2d-96cf-1aa43c0e552e]
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[Tiling][3087c3cb-8136-54ad-9049-93c6280f0113]
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[Tiling][68ef16ac-5493-5d0a-9dcb-4648b49eb91d]
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[Tiling][69c0e06a-f117-5771-ad69-811b02cae00e]
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[Tiling][desktop6][5b154f0f-f62a-4fce-a263-49503762a0c1]
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[Tiling][desktop6][5f0b7c9c-3df7-4dfd-9009-bdf18c7632be]
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[Tiling][desktop6][60acde4e-f6fa-47e5-b92b-ad49d2551dc6]
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[Tiling][desktop6][9d8d271e-3437-43d3-8bd6-669be75ef905]
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[Tiling][desktop6][cfbf3694-57a9-485c-9522-ac9bdefe8e79]
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[Tiling][desktop6][d7331781-2985-408d-ada2-e4ee97583b35]
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[Tiling][72d320c2-587f-52ba-8f7b-27165adc7433]
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[Tiling][7960cadb-dac0-503c-89e3-7fc98f66f9f3]
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[Tiling][81ac7ba7-2203-5903-a461-6d5b3020777d]
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[Tiling][desktop4][5b154f0f-f62a-4fce-a263-49503762a0c1]
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[Tiling][desktop4][9d8d271e-3437-43d3-8bd6-669be75ef905]
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[Tiling][desktop4][cfbf3694-57a9-485c-9522-ac9bdefe8e79]
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[Tiling][desktop7][5f0b7c9c-3df7-4dfd-9009-bdf18c7632be]
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[Tiling][desktop7][d7331781-2985-408d-ada2-e4ee97583b35]
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[Tiling][desktop8][5b154f0f-f62a-4fce-a263-49503762a0c1]
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[Tiling][desktop8][5f0b7c9c-3df7-4dfd-9009-bdf18c7632be]
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[Windows]
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