STEPS TO REPRODUCE 1. Enable the following three keyboard advanced options: "Compatibility options | Enable extra typographic characters", "Key to choose the 3rd level | Right Alt", "Switching to another layout | Win+Space". 2. They to switch layout via Win+Space. OBSERVED RESULT Nothing happens: layout isn't switched. EXPECTED RESULT Layout switches. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Manjaro Linux (rolling release, up-to-date to Set 17, 2020) KDE Plasma Version: 5.19.5 KDE Frameworks Version: 5.74.0 Qt Version: 5.15.1 ADDITIONAL INFORMATION If you disable extra typographic characters, layout switches. I remember this bug existed in Linux Mint, but I though it was Mint-specific.
That's because Win+Space is the default IBus shortcut for switching keyboard layouts; the two conflict. You can always change the shortcut in IBus's settings window by running `ibus-setup` in a terminal window or right-clicking on its system tray icon and choosing Preferences.