At the moment the button takes you to the next lesson that hasn't been completed. This gets very confusing for people. It would seem to make more sense to go to the next lesson especially as the default text already says that.

Right now if a participant is part way through a course and wants to go back through previous content they can get to their chosen lesson through the course sidebar. However if they wish to progress through each lesson from here, clicking “mark lesson complete” will jump them ahead to the next incomplete lesson.

An option for Previous lesson / next lesson buttons OR option to to adjust the functionality of the mark lesson complete button to progress to next lesson regardless of completion status would solve this issue.

Be mindful that most students complete on mobile, so aren’t looking at the sidebar in each lesson, so they can get confused as to what they have skipped or not skipped when progressing back through content. The change I requested should mitigate this confusion.