Windows corrupt when hovering over the task in task manager in KDE

[dev-jam]

Select the version

25.2.2

Describe your issue

When hovering over a task in the task panel in kde plasma with "Show small window previews when hovering over tasks" enabled, I am experiencing corruption of opened windows on the desktop. It can be any window, not particularly the window to be previewed. The window stays corrupt for the full hover duration and clears/corrects immediately on mouse-out. I suspect this started in version 25.2.x. The same happens when using a compositor, but less frequent.

I am using kde plasma 6.3.6 on Debian Trixie with modesetting on an Intel igpu on xlibre 25.2.1 and 25.2.2 without a compositor.

This seems different from #1924

I just noticed, something similar happens when maximizing a window, there is a brief moment of the same corruption in the window that is being maximized. Happens both with and without a compositor and it is sporadic, I have sessions where it does not occur at all. When disabling compositing again, my lower and upper panel shows similar corruption but the lower panel corrects itself again but the upper panel stays corrupted.

I also tested it on xorg X11 from the debian repo but it does not have this problem.
I also tested it on xlibre master from 2 days ago and it has the same problem but one difference, when mouse out, the windows stay corrupted until I focus or activate the window.

Steps to reproduce

1. Hover over a task in icons-and-text task manager
2. Try a couple of times, a window will corrupt

What did you expect?

Windows to stay correctly rendered

Additional Information

Extra fields

• I have checked the existing issues
• I have read the Contributing Guidelines
• I'd like to work on this issue

[dev-jam]

I have built the debs for 25.1.9 stable and the bug is gone.