SUMMARY If the focus is on the 'edit colour scheme' button, pressing alt+space to invoke krunner results in the button also being activated. STEPS TO REPRODUCE 1. Open the colour schemes selection screen (Appearance > Colours). 2. Press the edit button on a colour scheme. 3. Close the edit window which opens. 4. Now press Alt+Space to invoke krunner. OBSERVED RESULT Krunner opens, but immediately closes since the edit button also somehow detects the 'space' key and opens the edit window. EXPECTED RESULT Krunner should open, and nothing should happen in the system settings application. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Arch Linux KDE Plasma Version: 5.17.90 KDE Frameworks Version: 5.66.0 Qt Version: 5.14.0 ADDITIONAL INFORMATION I'm not sure if this is a bug in the system settings application, in krunner or in whatever handle keyboard shortcuts, but I'm reporting it here.
I've experienced this with other applications. Pretty sure it's somewhere in the krunner/kwin/plasma/dbus stack. Ways in which it the bug could live there are pretty obvious; ways in which kcmshell / a specific kcm could be at fault are difficult to imagine (aside from being deliberate, anyway). FWIW, in my experience, it seems more likely to happen either during a long-running session and/or when KF5 packages are upgraded during a session (i.e. before logging out and back in).
*** This bug has been marked as a duplicate of bug 416145 ***