SUMMARY When using Unreal Engine 5, I experience an unusual flickering issue when interacting with UI elements. This issue is most likely a problem with KDE, as it doesn't seem to occur on Gnome. I have attached a reference video of the problem. STEPS TO REPRODUCE 1. Download the source code for Unreal Engine 5 from GitHub (requires an Epic Games account, with a signed agreement). 2. Compile the source. 3. Open the engine and create a new project, then open the project. 4. Perform similar steps to those shown in the video (navigate around the UI for a few moments) to observe the issue. OBSERVED RESULT Unusual flickering and general graphical issues will interfere with the user interface. EXPECTED RESULT The UI would render normally without any unexpected artifacts. SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: Manjaro (Testing) (available in About System) KDE Plasma Version: 5.23.2 KDE Frameworks Version: 5.87.0 Qt Version: 5.15.2 Graphics Platform: X11 Graphics Processor: AMD DIMGREY_CAVEFISH ADDITIONAL INFORMATION As a pure guess, I suspect that the issue is being caused by KDE retaining some information about the previous frame(s) for too long and rendering it over newer frames.
If you have issues with viewing my attached video, then here is a direct link to it: https://forums.unrealengine.com/uploads/short-url/qgWPhpBrX7yBllaWLCi4koWI37D.mkv
This bug was reported against an outdated version of KWin. We have made many changes since the. If the issue persists in newer versions can you reopen the bug report updating the version number.