SUMMARY Some apps take about a second to have their window appear, after instantly showing as launched and active in the "Task Manager" section of the plasma panel. This behaviour is consistent for the affected apps. Launching the apps from a terminal and reproducing the behaviour does not show any errors. However, when reproducing the behaviour while running `journalctl -f` the following journal entry is consistently witnesses: kwin_wayland[1325]: kf.windowsystem: static bool KX11Extras::mapViewport() may only be used on X11 This happens consistently for the following apps: Discord [Flatpak] - restoring from tray Spotify [Flatpak] - restoring from tray Steam [pacman] - restoring from tray and opening any window, such as game properties Some examples of apps that work correctly, and don't exhibit the behaviour: Dolphin, Kate, Krunner KeePassXC [pacman] - restoring from tray Firefox [pacman] - new window Vesktop [Flatpak] - restoring from tray From what I gather, what the affected apps have in common is that they all run in xwayland. App example 1 - Discord STEPS TO REPRODUCE 0. Install a clean up-to-date OS with KDE Plasma, such as endeavourOS or cachyOS 1. Install discord: flatpak install flathub com.discordapp.Discord 2. Open discord, no need to log in 3. Close the discord window, so that it remains in the system tray 4. (optional) open a terminal window and run `journalctl -f` to see the yellow warning regarding KX11Extras::mapViewport 5. Left click on the discord icon in the system tray OBSERVED RESULT Apps using xwayland, such as discord, opening immediately in the "task manager" section of the panel, but takes about 1 second to actually make the window appear. EXPECTED RESULT Apps using xwayland showing immediately App example 2 - Steam STEPS TO REPRODUCE 0. Install a clean up-to-date OS with KDE Plasma, such as endeavourOS or cachyOS 1. Install steam, run steam and log into steam 2. (optional) open a terminal window and run `journalctl -f` to see the yellow warning regarding KX11Extras::mapViewport 3a. Close the steam window so that it remains in the system tray, then left click on the steam icon in the system tray 3b. Open any window inside steam, such as: friends & chat, steam settings, or game properties OBSERVED RESULT About 1 second delay when opening the main steam window from the system tray, or when opening a window from inside steam EXPECTED RESULT The main steam window or any windows opened inside steam appearing immediately without delay. SOFTWARE/OS VERSIONS (available in the Info Center app, or by running `kinfo` in a terminal window) Linux/KDE Plasma: EndeavourOS, 6.16.4-zen1-1-zen KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.1