Bug 510051

Summary:	Clicking grouped task when in "small window preview" sometimes shows nothing
Product:	[Plasma] plasmashell	Reporter:	robert.lofgren.larsson
Component:	Task Manager and Icons-Only Task Manager widgets	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	normal	CC:	kdedev, nate, qydwhotmail
Priority:	NOR
Version First Reported In:	6.4.5
Target Milestone:	1.0
Platform:	CachyOS
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	Desktop as is. Note the plus sign on the Steam Icon. Nothing happens when clicked.

Description robert.lofgren.larsson 2025-09-29 13:23:06 UTC

SUMMARY
When setting "Clicking grouped task:" is set to "Shows small window previews", sometimes this function stops to function, and alt-tabbing is the only way of accessing a window that's grouped. 
Reboot works as a work-around, and I haven't been able to find a pattern where this happens.

Switching to any other setting (large window preview, cycle through or textual list) all work. 
Switching back to small window preview doesn't solve the problem, it stays non-functional. 

STEPS TO REPRODUCE
1. Set "Shows small window previews" in the Behaviour part of Icons-Only task manager
2. Click a grouped window in the taskbar

OBSERVED RESULT
Nothing shows up

EXPECTED RESULT
A small preview of each window in the group should appear

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: CachyOS
KDE Plasma Version: 6.4.5 
KDE Frameworks Version: 6.18.0
Qt Version: 6.9.2

ADDITIONAL INFORMATION
n/a

Comment 1 Nate Graham 2025-09-29 19:50:58 UTC

Do you by any chance have an NVIDIA GPU?

Comment 2 robert.lofgren.larsson 2025-09-29 20:01:35 UTC

Yes, RTX 4070 Super. 
i9 11th gen, 64 gb ram. 

Wayland-session

Comment 3 TraceyC 2025-09-29 20:28:57 UTC

I'm not immediately able to reproduce this on a system with Plasma 6.4.5 and an NVIDIA GPU, but I'll keep an eye out

Comment 4 robert.lofgren.larsson 2025-09-29 21:22:11 UTC

Created attachment 185374 [details]
Desktop as is. Note the plus sign on the Steam Icon. Nothing happens when clicked.

Comment 5 robert.lofgren.larsson 2025-09-29 21:25:25 UTC

(In reply to TraceyC from comment #3)
> I'm not immediately able to reproduce this on a system with Plasma 6.4.5 and
> an NVIDIA GPU, but I'll keep an eye out

I have a few widgets downloaded, but not used. I assume that wouldn't cause any problems? 
System is patched regularly, like almost every day, as well as rebooted.

Comment 6 Nate Graham 2025-09-30 18:45:43 UTC

Since you have an NVIDIA GPU, it reminds me of Bug 480800. But that was supposed to be fixed in Qt 6.9, so likely not the exact same thing.

Comment 7 robert.lofgren.larsson 2025-10-28 05:32:52 UTC

Well, turns out I was using Vulkan as my backend-renderer. (I have no recollection of changing this on my own)
A lot of issues, along with this one, was solved after deleting .config/kdeglobals and rebooting.

I guess this can be set to resolved.

Comment 8 TraceyC 2025-10-28 14:49:44 UTC

Thanks for letting us know. I'll close this out for now. If the bug recurs, feel free to reopen the report.