Had my top box changed recently due to leaking
New top box lock fell out, with mine the 7th tag in the lock was missing and was in position 6.
Quick YouTube research and moved the 6th tag and its spring to position 7, refit into top box with the help of a thin bladed screwdriver and a nice "click" and the lock is securely now fitted.
Shame the dealer got one correct and not the second one, could have easily lost it on the way home :-(