Practice Test in Storyline - Doesn't Save Progress on Resume

I have created a Practice Test in Storyline so that students can practice/review all potential test questions prior to taking an actual test. There are 300+ multiple choice questions divided into multiple topics (each topic is it's own scene). They receive pass/fail after completing each topic and then, once they've completed all topics they get a cumulative final pass/fail result.  It works perfectly if the student completes all topics in one session. The issue I have is that, due to the length, I want them to be able to save their progress and Resume when they re-launch the course. However, regardless of how many scenes are completed, when they Resume they are always taken back to the same exact question each time in the middle of one of the topics. When they get back to the Main Menu, the scenes that they completed have not saved their progress. Any suggestions on what might be causing this and how to get their progress to save and when they resume?