See the video. SOFTWARE/OS VERSIONS KDE Frameworks Version: 5.71 Qt Version: 5.15.0
Created attachment 129703 [details] Video
I was experiencing this with Plasma 5.19, but with 5.20 (i.e. current git master) I'm not seeing it anymore. Any chance you could activate Arch's kde unstable repo and try again?
Kde_unstable only contains Beta or "higher" packages, I will try to build Kwin from source or download Kde neon.
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
I don't see this issue on KDE Neon unstable 2020-07-12. Assuming it's not caused by never kernel, Mesa, Qt or something else, It looks like it's fixed. I will reopen if it reappears in 5.20 Beta on Arch once it's available.
Created attachment 146446 [details] partial bold shadow example I've been seeing this problem with kwin 5.23.5 and for quite some time before this. Will test on 5.24 after I update my system. The effect seems to depend on screen location, happening along certain lines on the screen. In my case, the shadow becomes bold around the bottom part of the cursor (see attached photo) and the cutoff line lies approximately 150 pixels down from the top of the screen (screen resolution is 1920x1080). Near the top left corner there's a point where only the bottom-right corner becomes "heavy"; near the top right corner there's a point where that happens only with the bottom-left corner. When the cursor is partially over the panel and partially over a window above the panel, the effect is happening over both parts of the cursor independently (the shadow grows bolder, then resets to normal again, and resets happen separately for the top part and for the bottom part). Also, when the cursor is over the digital clock in the panel (with seconds enabled), every second change resets the shadow. In other words, it looks like if the shadow were being composed over the underlying image over and over, thus becoming less and less transparent, and reset when something causes that part to be recomposed from scratch. Gentoo Linux, Qt 5.15.2 with Gentoo-provided KDE patches, Frameworks 5.90, Plasma 5.23.5.
(In reply to Denis Lisov from comment #6) > I've been seeing this problem with kwin 5.23.5 and for quite some time > before this. Will test on 5.24 after I update my system. Just rebooted into 5.24, unable to reproduce so far. Not sure whether this problem happened straight out or reboot before, so I'll report here if it starts reproducing again.