SUMMARY While alt+tab task switcher/tabbox is fading away, the contents behind it are slightly blurred and offset until it's fully gone, then the content snaps back to normal. This only happens sometimes, oddly. See attached videos: first is the bugged behavior with two windows in tabbox, and the second is the correct behavior where the only thing I changed was having 3 windows in tabbox instead of two. OS: openSUSE Krypton (Tumbleweed + KDE git master, Qt 6.8.2, Wayland, amdgpu)
Created attachment 179805 [details] Bugged behavior
Created attachment 179806 [details] Correct behavior
Are you using a fractional scale factor? If you are, I think there's a plausible way it could be happening, though it'll still be the world's tiniest visual glitch! I'm amazed you were able to notice it at all. I had to pay very close attention in the first screen recording to notice it.
Hah, indeed tiny but sticks out like a sore thumb to me! I can't rest until every Plasma pixel is perfect :) I did mean to mention 150% global scale factor, yes!