Bug 506171

Summary:	Window Flickering in applications and panel
Product:	[Plasma] kwin	Reporter:	Kirby <strong.jet6169>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	kde, nate, strong.drum0546, teelarr
Priority:	NOR
Version First Reported In:	6.4.1
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Kirby 2025-06-25 16:16:47 UTC

SUMMARY

Myself and a few others seem to have an issue when using high refresh monitors and KDE. While using applications as well as just the panel, it seems as if the window itself is tearing and causing itself to be unrendered. What I mean by that is that while the issue is occurring, you are able to see your wallpaper through the active application. The windows will glitch in and out rapidly, causing a flicker-like effect. Unfortunately, replication is hard to do but the effect always returns. One way of mitigation I have found is to change my display's refresh rate from 240hz, down to 120hz. That seems to fix the problem resolutely; changing back to 240hz will seemingly fix the issue for a while but returns later.

I have been able to replicate this issue on Arch, Bazzite, and Nobara using the latest version of KDE at the time, leading me to believe it is some kind of issue between my equipment and the KDE platform. With that in mind though, after installing Gnome the issue was completely gone meaning the issue should lay somewhere on the KDE side. A post has been submitted on the KDE forums here: (https://discuss.kde.org/t/kde-panel-flicker-corruption/3093) and on another forum here: (https://sh.itjust.works/post/38436824).

STEPS TO REPRODUCE
1. Have a high refresh rate monitor
2. Use the system for a while if error is not present
3. The place I see the issue the most is when clicking the extension icon in firefox; the subsequent window that forms will almost always glitch out at the bottom.

SOFTWARE/OS VERSIONS

Operating System: Arch Linux
KDE Plasma Version: 6.4.1
KDE Frameworks Version: 6.15.0
Qt Version: 6.9.1
Kernel Version: 6.15.2-arch1-1 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7800X3D 8-Core Processor
Memory: 32 GiB of RAM (31.1 GiB usable)
Graphics Processor: NVIDIA GeForce RTX 4080 SUPER

Comment 1 Kirby 2025-06-25 16:18:01 UTC

Apologies, the correct link to the KDE forum is: https://discuss.kde.org/t/kde-panel-flicker-corruption/30931

Comment 2 Lenzoid 2025-06-30 20:43:52 UTC

Thanks for your report! Could you please take a look at this issue https://bugs.kde.org/show_bug.cgi?id=503458 and check if changing the color accuracy option to "Prefer color accuracy" makes it go away? The issue seem quite different since your flickers are not visible in the screen recording, but it's worth a try.

Comment 3 Kirby 2025-07-01 08:14:22 UTC

(In reply to Lenzoid from comment #2)
> Thanks for your report! Could you please take a look at this issue
> https://bugs.kde.org/show_bug.cgi?id=503458 and check if changing the color
> accuracy option to "Prefer color accuracy" makes it go away? The issue seem
> quite different since your flickers are not visible in the screen recording,
> but it's worth a try.

Hi Lenzoid,

My displays are actually already set to prefer color accuracy, although I did see the issue on the original setting of prefer efficiency. I could replicate the issue in that thread so I imagine the issues between me and them are pretty similar; however a trademark of my particular issue is the weird checkerboarding I see while moving windows around.  I've uploaded another video here (https://files.catbox.moe/tw1cbp.mp4) that I just recorded so you could see my particular issue.  Please let me know if there's anything else I can do to help.  Thanks!

Comment 4 Kirby 2025-07-01 08:17:17 UTC

(In reply to Kirby from comment #3)
> (In reply to Lenzoid from comment #2)
> > Thanks for your report! Could you please take a look at this issue
> > https://bugs.kde.org/show_bug.cgi?id=503458 and check if changing the color
> > accuracy option to "Prefer color accuracy" makes it go away? The issue seem
> > quite different since your flickers are not visible in the screen recording,
> > but it's worth a try.
> 
> Hi Lenzoid,
> 
> My displays are actually already set to prefer color accuracy, although I
> did see the issue on the original setting of prefer efficiency. I could
> replicate the issue in that thread so I imagine the issues between me and
> them are pretty similar; however a trademark of my particular issue is the
> weird checkerboarding I see while moving windows around.  I've uploaded
> another video here (https://files.catbox.moe/tw1cbp.mp4) that I just
> recorded so you could see my particular issue.  Please let me know if
> there's anything else I can do to help.  Thanks!

Sorry, another quick thing is that the flickering only ever appears in the bottom right corner of the monitors. If you were to split up the monitor into quadrants, it'd be isolated just down there; I've never seen the issue appear anywhere else. I tried highlighting that in the video I just uploaded where I go to the second monitor.

Comment 5 teelarr 2025-11-27 04:43:35 UTC

Apologies if commenting on an old bug is discouraged. 

I searched for this bug and found this issue. I can repro this on OpenSUSE Tumbleweed and Fedora on an Alienware AW3225QF @ 240hz if I open Steam and drag it to the bottom right of the screen, both using latest Plasma 6.5.3 on an NVIDIA RTX4090 running the latest 580 driver. Is there anything I can provide to help debug?