Bug 504471

Summary: [VISUAL GLITCH ON EXTERNAL SCREENS] Flashes of the desktop or other application windows below
Product: [Plasma] kwin Reporter: mrangelrcd
Component: multi-screenAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED UPSTREAM    
Severity: normal CC: xaver.hugl
Priority: NOR    
Version First Reported In: 6.3.4   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Video showing how the flashes look

Description mrangelrcd 2025-05-18 14:35:26 UTC
Created attachment 181458 [details]
Video showing how the flashes look

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Quick flashes of the desktop, or other windows below the current visible window appear when I'm using an external screen. It does not happen on my laptop's built in screen. These glitches can happen in any application (dolphin, firefox, games, etc...).

I've tried on multiple different screens and cables and the bug still occurs. I have the impression that the flashes show up more frequently when I use a 2k screen instead of the 1080p I normally use but I'm not 100% sure.
***

**SOFTWARE/OS VERSIONS**
Operating System: Nobara Linux 42
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.0
Kernel Version: 6.14.6-200.nobara.fc42.x86_64 (64-bit)
Graphics Platform: Wayland
Processors: 16 × AMD Ryzen 7 7840HS w/ Radeon 780M Graphics
Memory: 14.8 GiB of RAM
Graphics Processor 1: AMD Radeon 780M
Graphics Processor 2: NVIDIA GeForce RTX 4070 Laptop GPU


ADDITIONAL INFORMATION
Comment 1 Zamundaaa 2025-05-19 16:13:39 UTC
(In reply to mrangelrcd from comment #0)
> I've tried on multiple different screens and cables and the bug still
> occurs. I have the impression that the flashes show up more frequently when
> I use a 2k screen instead of the 1080p I normally use but I'm not 100% sure.
This looks a lot like synchronization going wrong, so that would make sense.

Because of bug 504086 about similar glitches, with only an NVidia GPU, I'm reasonably certain that this is a bug in the NVidia driver. Please report it at https://forums.developer.nvidia.com/c/gpu-graphics/linux