I want to disable some Ubuntu (Ubuntu 16.04.4 LTS) system shortcuts
I tried System Settings > Keyboard > Shortcuts and then select the undesired shortcut to disabled it.
After reboot, the shortcut still works
I tried dconf Editor : org > gnome > desktop > vm > keybindings then select the undesired shortcut and set the value to ['disabled']
Doesn't work either : I can still use the shortcuts
The concerned shortcuts are Ctrl + Alt + S (toggle shading) and Ctrl + Alt + L (lock screen).
Am I missing something here or can I use another way to disable these shortcuts ?