Fedora Asahi 40 : unexpected thin black lines around mouse cursor


Hello everyone,

Since my upgrade to F40 (iMac M1) , some thin black lines often appear around mouse cursor when I move it locally (for example, when doing some little circles with the cursor).
(see below, zoomed picture of a white area in a pdf opened with Okular).

I’m sure I never saw those with f39.
Those lines disappear after a few seconds or when I scroll or move the window.
My f40 is up to date and I use a fractional scale of 165%.
It’s not critical, I can live with that, but I can live without too :wink:

Is it a known bug or can some settings fix this ?

Thanks very much for your answers.

Almost certainly a fractional scaling refresh/redraw bug in KWin (165% is a rather odd number so probably few people have tested that one). They’ve had a bunch of these and it actually got a lot better with F40/Plasma 6 in general, but it sounds like they might still have some minor issues there…

I suspect if you change the scale a little bit (e.g. 150%, which is much better tested) you’ll see different behavior.

Your suggestion works.
No black lines since I changed the scale as you advised (150%).
Thank you very much.

Probably worth filing upstream at bugs.kde.org then :slight_smile: