SUMMARY On a multi-monitor setup, a window whose left edge should be exactly aligned with the edge of a screen bleeds 1 pixel leftward, intruding into the adjacent display. STEPS TO REPRODUCE 1. Have two 1920*1080 screens, arranged horizontally next to each other. 2. In Plasma, open a non-maximised application (let’s say Dolphin) 3. Half-tile the window to occupy the left half of the right-hand monitor. Or alternatively, use kdotool windowmove to position it at (1920, 0) - the issue isn’t specific to using the tiling feature. OBSERVED RESULT A 1-pixel wide vertical strip of the window appears at the right-hand edge of the left-hand screen. EXPECTED RESULT The left-hand edge of the window occupies precisely the left-hand edge of the right-hand screen, with no bleed into the left-hand screen. SOFTWARE/OS VERSIONS Operating System: Fedora Linux 43 KDE Plasma Version: 6.5.4 KDE Frameworks Version: 6.22.0 Qt Version: 6.10.1 Kernel Version: 6.18.4-200.fc43.x86_64 (64-bit) Graphics Platform: Wayland ADDITIONAL INFORMATION I'm not positive that Plasma 6.5.4 specifically introduced this, but it's a pretty recent issue. I think it's appeared only in the last ~2 months.
I should add, my theme is the stock "Fedora" theme, which is very similar to standard Breeze.
I think this isn't specific to multi-monitor setups (though it's more visually noticeable in the multi-monitor configuration I described). For example, in default Breeze (therefore no window borders): 1. Set the wallpaper to solid red (so the effect is easy to see) 2. Open a window 3. Use kdotool to reposition the window to x=1, y=0 Expected result is a 1-pixel wide strip of red (from the wallpaper) at x=0. Instead, the x=0 strip is occupied by the left-hand edge of the window and you can't see any red.