I can create and use a custom shortcut ("Global Shortcut / Command/URL") successfully.

However, editing the "Action" after it is created is not possible.

Reproducible: Always

Steps to Reproduce:
1. Goto "System settings / Shortcuts / Custom Shortcuts" or run "kcmshell5 khotkeys"
2. Create a new "Global Shortcut" of type "Command/URL", e.g.:
- Shortcut: Meta+.
- Command/URL: xdotool type $(date +"%d.%m.%Y")
3. "Apply" and close the dialog.
4. Goto "System settings / Shortcuts / Custom Shortcuts" again.
5. Edit your Shortcut, e.g. try to change Command/URL to : xdotool type --clearmodifiers $(date +"%d.%m.%Y")
6. "Apply" and close the dialog. (There is no error message).


Actual Results:  
The change to the shortcut action (Command/URL) never gets saved.
The custom shortcut must be deleted and recreated to apply changes.

Expected Results:  
The change to the shortcut action (Command/URL) should be saved and applied.

Fully updated Arch Linux
System Settings 5.4.3
Using KDE Frameworks 5.16.0
QT 5.5.1