SUMMARY Setting Left Ctrl + Left Shift as shortcut for switching keyboard layout changes the normal behavior of Left Ctrl + Left Shift + other keys. For example, in a text editor Ctrl+Shift+arrowLeft should select the word on the left of the cursor, but now it just moves the cursor to the left of the word. Ctrl+Shift+T in a browser should re-open the last closed tab, but just opens a new tab (like Ctrl+T does). (Only tested under Xorg, not Wayland) STEPS TO REPRODUCE 1. Go to Settings > Hardware > Input Devices > Keyboard > Layouts 2. In Shortcuts for Switching Layouts > Main shortcuts, select Left Ctrl + Left Shift 3. Try using any shortcut comprising Ctrl+Shift+[another key] OBSERVED RESULT Pressing Ctrl+Shift+[some key] behaves like Ctrl+[some key], as if Shift wasn't pressed EXPECTED RESULT normal keyboard behavior SOFTWARE/OS VERSIONS Kernel version: 5.15.21-1-MANJARO (64-bit) KDE Plasma Version: 5.24.2 KDE Frameworks Version: 5.91.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION Also had this bug in a Ubuntu laptop, but I didn't collect details
That's probably XKB-specific behavior as it consumes the combination on key presses immediately: https://gitlab.freedesktop.org/xorg/xserver/-/issues/258 We could try to overrule that on Plasma side with modifier-only shortcuts but that's another story.