Pop quiz questions - saved state

I have some one-off questions that I have included at the end of a couple of scenes within a training.   In the question slide properties the NEXT and PREVIOUS buttons are not selected (only the SUBMIT option).  These questions are not scored as part of the final assessment – they are just pop quizzes in the training.   

As well as the Retry Quiz option at the end of the final assessment, if a person is not successful I have included a Review Training button on the failure layer of the results slide.  I want the user to be able to review the training but not have to retake the pop quiz questions. 

Issue I am encountering if I try to review the training after failing the final assessment.

If I set the pop quiz question slides as ‘Reset to saved state’  the NEXT and PREVIOUS buttons appear on the player when I revisit the questions slide, however whilst the PREVIOUS button works the NEXT button doesn’t.   It looks like there is a automatic preset within Storyline to include these buttons if Saved state is selected and question slide is revisited however the NEXT button is not working.

I thought I might be able to include a trigger to Jump to the next slide/scene when user clicks on NEXT button (which replaces the SUBMIT button when the saved question slide reopens) but because NEXT is not selected in the slide properties this is not available in the trigger edit menu – only the SUBMIT button. 

Is there a way to include a condition or variable to make this work or will I have to reset to initial state and users will have to retake the pop quiz questions.  

Any advice you can provide re  would be greatly appreciated.

Thanks

Cath