Choosing "Leave blank" lets a student bypass the "Repeat until correct requirement"

1. As an instructor, I chose the Repeat until correct option

2. I logged in as a student and took the quiz.

When the wrong answer was chosen, I was presented with feedback showing the correct answer plus a place to enter my new answer.

I chose "Leave blank" and was allowed to finish the quiz.

That shouldn't happen. I should not be allowed to finish the quiz without repeating the question until it's correct.