Results Slide Not Loading

I would save the file with a new (different) name, use a new results slide inserted immediately before the existing one, and then see if that one works. I've had a few courses that had this same problem and this was the only way to get all of the intermittent knowledge checks to report correct results.

You end up having a meaningless results slide (the existing one that isn't working correctly); I just created an empty scene that has nothing connected to it and moved the slide there. The course now works fine.