Bug 466200

Summary:	Region artifacts that follow mouse ghosting when all windows set to semi-transparent on Wayland with multi-monitor setup
Product:	[Plasma] kwin	Reporter:	Pasha <kutikovpasha>
Component:	wayland-generic	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	NEEDSINFO WAITINGFORINFO
Severity:	normal	CC:	nate
Priority:	NOR
Version First Reported In:	5.27.1
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Pasha 2023-02-21 16:21:57 UTC

STEPS TO REPRODUCE
1. Have multiple monitors
2. Start KDE Wayland session
3. Set window transparency (through window rules)

OBSERVED RESULT
1. Cursor trail on desktop.
2. Main display (bottom-right). Bottom right portion of the screen is black, mouse movement in the top-left corners "wipes" black window away, similar to mouse trail.*
3.  Additional display (top). Right border of the screen is black, mouse movement in the left border "wipes" black window away, similar to mouse trail.*
* Happens both on desktop and all applications.

EXPECTED RESULT
No artifact regions and no mouse trail

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: Arch Linux (6.1.12)
KDE Plasma Version: 5.27.1
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8

ADDITIONAL INFORMATION
Nvidia proprietary driver, different refresh rates on all screens (120, 75, 60).
Turning blur off, turning any of the screens doesn't fix the issue.
Leaving only 1 display fixes the issue.
Monitor setup: https://postimg.cc/ZWkBxZXf
Bug showcase: https://youtu.be/tIT0kHvEeWY

Comment 1 Nate Graham 2023-02-21 22:37:24 UTC

Bug 455526?

Comment 2 Pasha 2023-02-22 07:40:45 UTC

(In reply to Nate Graham from comment #1)
> Bug 455526?

Mouse behavior is the same as in the bug, that you've provided. And it was the same for me prior to 5.27 update. 5.27 brought the bug that you can see in the youtube video in the bottom of my bug report (should I move it to the attachments?) and it is not displayed in the 455526 report.

Comment 3 Vlad Zahorodnii 2026-01-22 14:35:08 UTC

Does the issue still happen in 6.5 or 6.6?

Comment 4 Bug Janitor Service 2026-02-06 03:50:27 UTC

🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

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