Created attachment 139235 [details] rendered over desktop, lower right corner of the right screen. SUMMARY STEPS TO REPRODUCE 1. 2 displays 1920x1080 2. set left one to portrait mode , 90' Counter Clockwise rotation (1080x1920) 3. right display is standard 1920x1080 4. offsets +0+0 (left) +1080+420 OBSERVED RESULT Renders 6 gray pixel line in bottom right of horizontal screen (right one) moving offset to +1080+419 makes it disappear, increasing offset makes it go up. Increasing horizontal offset makes it move to left. 6 pixel gray/dark gray line stays over everything with exception of mouse cursor when it covers it. EXPECTED RESULT No unwanted pixels on the screen. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.22.0 KDE Frameworks Version: 5.82.0 Qt Version: 5.15.2 Kernel Version: 5.12.9-arch1-1 (64-bit) Graphics Platform: X11 Processors: 4 × Intel® Core™ i5-3570K CPU @ 3.40GHz Memory: 15,6 GiB of RAM Graphics Processor: NVIDIA GeForce GTX 970/PCIe/SSE2 ADDITIONAL INFORMATION I'm guessing someone made some hacky code to render something bellow screen and now it shows up in multi display setup when there's something 'bellow' that screen. There's no issue on SDDM, terminal or windows, only in kde. That said sddm seems to use x11 config, in this case i made main, right screen +0+0, and left rotated one -1080-420 which might have made it go away.
turns out it's not kde, ibus. if anyone googles this page: ibus settings + libkkc caused the error show property panel in ibus properties needs to be set to hide automatically, otherwise kkc leaves this mini pixel line.