Created attachment 156825 [details] Popup appearing, slowed to 15% speed SUMMARY *** NOTE: If you are reporting a crash, please try to attach a backtrace with debug symbols. See https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports *** Maybe every 20th time, sometimes even more frequently (very random), when opening popups of various applications, they visually flicker disturbingly, this happened for me in jetbrains rider, vscode and unity3d so far. In IDEs it's especially disturbing as auto completion opens and closes popups at a high rate, making this glitch occur quite a lot more frequently. While recording it i noticed that when it glitches it actually just shows the top left of my desktop. Enabled related desktop effects are "Fading Popups Kinetic" (installed) and background contrast and , but this also happens without any of them enabled, it's just visible for like a single frame instead of a few in that case. STEPS TO REPRODUCE 1. open popups in one of the mentioned applications repeatedly 2. Notice it sometimes rendering the desktop into the window content for a short period 3. acknowledge it as an issue OBSERVED RESULT (At random times) flickering popups, rendering the desktop as content briefly before showing their actual content EXPECTED RESULT Smooth, non-glitchy popups, rendering their own content or a default color or what's actually behind their rectangle from the start SOFTWARE/OS VERSIONS Linux/KDE Plasma: Kubuntu 22.10 (available in About System) KDE Plasma Version: 5.25.2 KDE Frameworks Version: 5.98.0 Qt Version: 5.15.6 ADDITIONAL INFORMATION I'm not sure if kwin or compositing is the correct category for this issue, as i don't have the technical knowledge about what makes up my desktop internally; it might be related to something completely different, it just seemed correct to me.
Thank you very much for the detailed bug report! What UI toolkits are those apps built with? VSCode I know is Electron; can you find out for JetBrains Rider and Unity3D? If they're all or mostly different, it increases the chance it's a KWin compositing issue. Out of curiosity can you reproduce the issue on Wayland? Also please note that Plasma 5.25 is no longer eligible for support or maintenance and I would strongly recommend upgrading to 5.27 as soon as your distro offers it to you. Plasma is a fast-moving project, and bugs in one version are often fixed in the next one.
Thanks for the fast answer. I'm surprised it is not eligible for support anymore. I transitioned my system to kubuntu just a week ago with a freshly downloaded official iso (LTS version) which i later upgraded to 22.10 as i had boot issues that where resolved by upgrading. I also don't know how i can upgrade my plasma version to something else than what's provided to me through the official channels, which i believed to be most up to date. I forgot to mention that i have an nvidia gpu (gtx1060 6gb) and i'm using the proprietary drivers as i've read that these work better and they indeed do with no other glitches or issues so far (UHD 3440x1440px, 120hz monitor). I also read that there currently are known issues with nvidia cards on wayland which i don't want to experiment with as i use my pc for work (i've been burned by that in the past whenever i tried running linux on my pc). This time it works quite stable so far (apart from this glitch) so i don't want to risk needing to reinstall or even revert to windows. As for the applications; i think i made an error when i said vscode is part of the list, i just tried reproducing it and it actually doesn't seem to occur there, but unity3d and jetbrains rider definitely present that issue. I wasn't able to find out what gui toolkits they build on, unfortunately; the best i could manage to find was this about intellij (which is the same base as rider): https://stackoverflow.com/questions/12309569/what-gui-libraries-are-the-jetbrains-using# and that the intellij community edition (source) might tell what's necessary but i'm not experienced in navigating java source code, so i'm a little lost in finding the answer there. As for unity3d, there's very little info and none openly available about what gui toolkit it uses. but i suspect it may even be using its own (like godot); here it only lists the basic system requirements: https://blog.unity.com/technology/announcing-the-unity-editor-for-linux Sorry to be of so little help.
Ubuntu is a discrete release distro so it's chronically behind what its upstream projects (e.g. KDE) are doing. Just a sad fact of life when using that distro. Trying the Wayland session won't wreck your PC; it should be safe.
I tried wayland, and it indeed had issues, but i was able to start unity and rider to test their behaviour. There it's somewhat different; it doesn't flicker just sometimes and with the desktop glitching inside the window content, but instead every time a popup appears, only with a black background as content. It's a little less distracting because it's atleast a plain color instead of visual noise, but it's still there in a way. Although i would prefer that or better a neutral grey or even the theme's window color to the current behaviour.
Thanks for the info!
i managed to upgrade to 5.27 via some post i found online (using the backports ppa). Now it's a little less glitchy. It doesn't flicker the background through anymore, now it just flashes black as in the wayland session. This is a little better. It's somewhat similar to https://bugs.kde.org/show_bug.cgi?id=441242 which i also experience. This may be linked as i believe the popups mentioned here seem to be (classified as?) windows from what i could gather, atleast they respond accordingly when i change animation settings for window fade-ins etc.
I just noticed that this does no longer seem to happen. Maybe it was fixed with the upgrade to 23.04, not sure exactly when it stopped, but it's a lot smoother now.