I performed an experiment where I installed a basic Debian stretch in a VM. Then I installed KDE and saw that it was working fine. Then I installed ibus. KDE continued to work fine. I saw ibus was running and there was the ibus icon in the tray. If I exit that, the keyboard stopped working. Why does ibus start automatically in a KDE session but just installing it? Exiting ibus shouldn't break my keyboard, it should just turn off input method features.