Navigation showing Lesson x of x

Dear community, I am trying to get rid of the lesson numbers from the navigation pane and it is not working for me. I have:  

1. Opened my course.
2. Selected Theme.
3. Selected Lesson Headers.
4. Scrolled to the bottom of the Lesson Headers settings.
5. Turn Lesson Count Labels Off.
6. Selected Save.

Can someone explain why it doesn't go away?