SUMMARY XWayland applications have heavy graphical glitches when selecting "Apply scaling themselves". STEPS TO REPRODUCE 1. Open Display Configuration 2. Select "Apply scaling themselves" for Legacy Applications 3. Reboot 4. Start XWayland application (tested with Signal via Flatpak and Intellij via Snap) 5. Notice the graphical glitches OBSERVED RESULT Graphical glitches which make the applications unusable EXPECTED RESULT No glitches SOFTWARE/OS VERSIONS Operating System: KDE neon 5.26 KDE Plasma Version: 5.26.0 KDE Frameworks Version: 5.98.0 Qt Version: 5.15.6 Kernel Version: 5.15.0-50-generic (64-bit) Graphics Platform: Wayland Processors: 12 × Intel® Core™ i7-10750H CPU @ 2.60GHz Memory: 31,1 GiB of RAM Graphics Processor: Mesa Intel® UHD Graphics ADDITIONAL INFORMATION KDE Frameworks is still on 5.98 instead of 5.99. Is 5.99 required for this to work? Neon currently only ships 5.98.
With that same CPU and GPU, I don't see any graphical glitches with Discord, VLC, or Chromium. Can you attach a screenshot of the issue?
Created attachment 152754 [details] Glitches in VLC menu Here you can see some glitches in VLC. As soon as I move my mouse, all highlighted entries begin to flicker. I had to use an external camera to take the screenshot because the glitches do not show up when using Spectacle.
Yikes!
Turns out the glitches only appear when the display is scaled to something higher than 100%. With 75% scaling or 100% scaling no bugs are present.
I experienced these glitches on my notebook, which has a Intel integrated GPU and a discrete Nvidia GPU. When setting the "PRIME Profiles" in Nvidia settings to "Intel" the glitches go away. When the glitches appeared I had it on "Nvidia On-Demand". So it seems it is probably an Nvidia driver issue.
Fixed by updating the nvidia driver.