Fixed Question Responses

Hi

Apologies if this has been covered before, couldn't find anything with the search function.

In my Storyline candidates are required to navigate from a Navigation Menu at the start through different sections, each of which consists of 2-3 slides of content and then 2 questions covering the content in the previous slides. Once they complete the questions they are shown a results slide, either "Well done!" or "You may wish to revise this section before the end of module assessment." and then automatically navigated back to the main menu.

Once they return to the main menu the button for that sub-section is greyed out and they are advised to continue with the next one. However, if they so wish they can return to a previously completed sub-section to review that content. When they do this, the first question has effectively reset allowing them to re-input their responses, whereas the second question's responses are fixed and they cannot change their previous answer. I'm not sure what is different between the 2, as all of the settings appear to be the same. We would like both questions to be "Fixed Response" if that makes sense, with no option to re-do if they navigate back to a previously completed question.

Does anyone know which settings are responsible for this, and how to fix the responses so they stay the same even when a candidate goes over slides they've already seen?

Please let me know if anything needs clarification, appreciate that might be quite a confusing explanation!