Created attachment 159086 [details] [Wayland] Thumbnails generation is slow and causes CPU considerable usage The way thumbnails are generated is slower than what is proven with X11, the appearance of the tooltip is laggy and the generation of thumbnails finishes after 1 second, this makes the whole Task Manager slow when the mouse pointer passes fast over its items.
Is this any better in any versions of Plasma 6? If not, what's your hardware? Can you paste the output of `kinfo`?