Quiz slides sometime shows Prev/Next and not Submit

I've already opened a support ticket, but I wanted to add here that this is happening to me in Storyline 360. We were directed to seek help from our LMS provider, so I am currently in talks with them about this situation. So hard to diagnose the problem when it is only happening to a few people and not everyone!

This is happening randomly on ungraded test questions with 'automatically decide' set on the revisit. No next or previous button is active on these slides, only the submit button. This has never caused issue before in the package running in the LMS for over a year, however after making a small change to question content and republishing, random users (10 out of approx. 125) are receiving next/prev buttons on random ungraded questions.

As Marie said, if the question is at the end of the scene and the next/prev buttons appear, the user is stuck and cannot proceed. Unfortunately, we don't use the menu, so there is no way for the user to proceed and they must start completely over, or we have to create a special package for them that has the content that they have already seen removed.

I'm going to change the revisit setting on the review questions to 'Reset to Initial State' today and test in a live environment next week to see if the problem is still occurring. Hoping that if we change this setting, if the user logs out of the class when this happens and then gets back in, it will have the submit button as intended. Wish me luck! ;)