What
If a page on the 3rd level in the menu hierarchy has child pages, then it will not act as a link to the page in the 3rd level of the menu, but the 3rd level page link gets repeated in the 4th level menu as a first link in the list. You have the option to give a different link text to be displayed on the 4th level menu if you wish to do so to avoid having the same link text repeated.
Where
Changing the repeated menu link text applies only to pages on the 3rd level in the menu hierarchy.
Do
Keep the menu links short and on-point.
Don't
Use long and detailed link texts.