Storyline Resetting Progress During Quiz

We're currently having an issue where if a learner leaves the course during the content, they will rejoin where they left off. However, if a learner leaves during the quiz/assessment section,  they are reset to the very beginning of the learning content.

As it's a timed and restricted module, the learner will have to go through 30 mins of content again before being able to access the assessment. 

Is there anything I can do in Storyline to prevent this from happening, or is it an LMS issue?