SUMMARY I don't know why and when this happens as no conflicts exists, but it does seem to be happen at random times. In most cases a reboot fixes the issue, a reset (default button) in Dolphin keyboard shortcuts doesn't fix it. I haven't changed any settings that could lead to this error. Maybe this is related to something else? STEPS TO REPRODUCE 1. Select file 2. Hit 'Shift+Del' 3. The key sequence Shift+Del is ambiguous. [..]. OBSERVED RESULT No action will be triggered. EXPECTED RESULT Perform the action (Delete). SOFTWARE/OS VERSIONS Windows: N/A macOS: N/A Linux/KDE Plasma: 5.20.4 (available in About System) KDE Plasma Version: 5.20.4 KDE Frameworks Version: 5.77.0 Qt Version: 5.15.2 ADDITIONAL INFORMATION I'm using IBus + US Int. layout (with deadkeys) on Arch Linux.
Known issue, already fixed in Dolphin 20.12.1. Sorry for the mess.