Keyboard shortcut to Downloads kick-start

I have set a custom shortcut in "System Preferences> Keyboard> Keyboard Shortcuts" specific to Safari which assigns a shortcut to the menu option "View> Show Downloads" which works, but only *after* the menu has been accessed by the mouse.

This seems quite bizare to me, completely going against the grain of the nature of what keyboard shortcuts are all about.

Can anybody replicate this behaviour, it only need be done once and then it's fine, it just needs that initial push-start.

Thanks.