See the video here https://www.youtube.com/watch?v=LxodJC2CdTg This is using Plasma, Qt 5.15.1, KF 5.74.0, X11 Can't reproduce it, just happens seldomly from time to time, scrolling in the view fixes it. So yeah unreproducible bug, probably not a very useful report, mostly wondering if i'm the only one that as seen it.
Looks awful :/ But yes, no idea how to get that.
I've not seen this myself either. Could be a graphical issue due to a driver maybe?
Given that kate is the only program i get this, even if it was a driver issue, i don't care, it's a kate issue :)
seems an update may have fixed it, so most probably wasn't really kate's fault