"Finish" button in Question Set questions
In a Question Set, the "Finish" button appears beside the "Prev" button when two conditions are met:
1) all questions are answered
2) the currently visible question is the last one
At the same time, a Question Set enables the user to answer questions in any order (and that's ok). So, many users answer the last question in the middle and end up the quiz e.g. on question 7. But the "Finish" button does not appear to them, although they see by the color of progress dots that all questions are already answered. It's not intuitive that it's necessary to click on the last question in order to finish the quiz.
This introduces confusion and users complain that they can't see the solution.
I think that for consistency, the Question Set should either enforce answering the questions from first to last, or show the "Finish" button for any question the user is currently viewing (as soon as all questions are answered). Of course, the second solution gives much more freedom for the whole interaction.