Storyline 360 Quiz navigation

Hi

I have a quiz with a fair few questions with a 100% pass mark (its open book, so I am not being too harsh)and each question has 3 attempts ... if anyone fails to answer correctly in 3 attempts they go to the failure page where I have a retake quiz button - the button has 2 actions

1. Reset the results slide (resetting only incorrect questions)

2. Jump to the slide before the 1st question

All works well ... if I get a question wrong 3 times it takes me to the failure page, I press the Retake Quiz button and it takes me to the correct slide and all questions I have answered correctly don't need me to answer them again (they weren't reset) ... BUT ... I now have to submit every subsequent question twice before the quiz will accept the answer and progress to the next question, i.e. I select the answer, it says correct, I press continue, nothing happens, I select the answer again, it says correct, I press continue, the next question appears

PS the quiz works perfectly if I answer them all correctly.

Any help will be gratefully accepted.

Cheers