screen-reader issues- need some help

I have a sample of a short, possibly 508 compliant up on a website to show to a few reviewers. I wanted them to be able to go through it more than one time, but even with a "Begin again" button on the quiz-score slide, they can go through it but not make any changes, even in a quiz slide that was not scored, just a multiple-choice question slide.

Is there a way to allow a complete restart once they have submitted a quiz result? I just want this as a temporary means, on this particular sample, so people can take several runs through the course and make different selections to make sure everything works okay.

On a video one reviewer sent me of the screen-reader results, the reader keeps saying "Graphic" every time it reads text, sometimes in the middle of a sentence.  What's that about?

The final score doesn't read aloud properly, either. Although there are numbers and percentages on the slide, the voice reads..."percent percent percent  resut stop score percent percent....etc."

Has anyone else encountered this?

Thanks