Bug 509022

Summary:	Cannot move mouse cursor between screens under Wayland
Product:	[Plasma] kwin	Reporter:	Lukas Sommer <sommerluk>
Component:	multi-screen	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED NOT A BUG
Severity:	major	CC:	kde, sommerluk
Priority:	NOR
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	screenshot.png

Description Lukas Sommer 2025-09-02 09:06:38 UTC

SUMMARY
Cannot move mouse cursor between screens under Wayland.

I have a left screen and a right screen. When I installed Kubuntu 25.04, using Wayland, it worked correctly at the beginning: I could move the mouse between both screens, while having a little barrier between (which is quite practical).

However, last week, this stopped working, and since then I cannot move the mouse to the other screen at all. 

SOFTWARE/OS VERSIONS

Operating System: Kubuntu 25.04
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.3
Kernel Version: 6.14.0-29-generic (64-bit)
Graphics Platform: Wayland
Processors: 8 × Intel® Core™ i7-7700HQ CPU @ 2.80GHz
Memory: 15.5 GiB of RAM
Graphics Processor 1: Intel® HD Graphics 630
Graphics Processor 2: llvmpipe
Manufacturer: LENOVO
Product Name: 80WK 
System Version: Lenovo Y520-15IKBN

ADDITIONAL INFORMATION

When I left-click-and-hold the title bar of a window, and then I move the mouse cursor (holding the window) as fast as I can to the other screen, I have a 30%-chance that it actually goes to the other screen.

If I start an X session instead of a Wayland session, I actually CAN move correctly the mouse cursor. (However, after weakup after standby, Plasma is broken on the right screen, no more panels nor screen background, so that's not an actual alternative either.)

I have a second user account on the same machine, where it works correctly on Wayland.

Comment 1 David Edmundson 2025-09-03 15:56:22 UTC

Can you check if there's a gap between your outputs in the screen configuration screen

Comment 2 Lukas Sommer 2025-09-03 16:31:56 UTC

Created attachment 184684 [details]
screenshot.png

Indeed, you're right, see attachment. I didn't remember to have changed this setting, but there seems to be a gap.

And yes, when I remove the gap, it works as expected.

Thank you!