SUMMARY Window does not render properly at size larger than 16384x16384 under both Xorg and Wayland sessions. STEPS TO REPRODUCE 1. Stretch the window horizontally or vertically to greater than 16384 pixels. OBSERVED RESULT Window Cannot render properly. The window will appear black or include only random artifacts at the time when the size exceeds 16384 pixels horizontally or vertically. EXPECTED RESULT Window should display normally. SOFTWARE/OS VERSIONS It appears on any major Plasma versions. The issue persists on Plasma 6.0 Dev.
16384 is the maximum texture size most GPUs (or at least the drivers) can handle, and thus without trickery on the application side, the maximum size of a window. There's nothing we can do about this.