Unfortunately, the shortcut Shift-Ctr-Alt-C has been deprecated in the latest version(s) of Blender: Blender 2.8. The only way to access the Set Origin command as of now is to either through Object > Set Origin,
or via the right-click/W key menu (depending on your keymap; refer below).
Of course, you could just switch to the old Blender 2.7x keymap via the
Keymap section in the Blender Preferences, which would allow you to use the Shift-Ctr-Alt-C shortcut,
although I highly doubt that the devs would consider updating it with every new release of Blender, so it would be recommended to just use the first two methods.
I understand your query to its full extent now. The behaviour that Blender does not offer the menu for the keyframing action along with the suggestion in the search-bar menu is not a bug; it is supposed to happen (it will pop-up once you click on the "suggestion"). However, if you still feel that it is indeed a bug, feel free to report it to the Blender Open Report Bug Tracker.