Can't turn off automatically moving words to known

In Settings, I unchecked “Paging moves to known”. But, when I exit a lesson, it still moves all the remaining blue words to known.
What step am I missing?
(Mac, Chrome)

Even if you have the 'Paging moves to Known" option disabled, once you complete a lesson, all remaining blue words from it will be moved to Known, that is how it works.