Quiz "Next" Button - still shows up after disabled

In my Storyline project (call it Part B), I have a quiz that draws from a question bank. In the slide layers tab, the "Previous" and "Next" Buttons are deselected, while the "Submit" button is enabled. However, when previewing the quiz, "Next" is still showing up.

I've tried restarting, deleted the whole scene that contains the quiz and rebuilding it again, and nothing seems to work.

In addition, I have another project (call it Part A) that is seemingly formatted the exact same way as Part B, with all the exact same triggers and slide layers, but the "next" button doesn't show up. I've searched all through the project, and it seems that Part A and Part B are identical in how the quizzes are structured and formatted.

Any advice or insight would be appreciated!