Captivate course shutting down in same spot for multiple users

Created a Captivate 13 course with 112 slides. Had the Completion rate set at 80% for the LMS system. There are a handful of users taking the course that have experienced it shutting down in about the same spot, approximately 80% through the slides. The LMS then generates a completion certificate and if they reopen the course, they have to start over, as it shows them as complete. Shouldn’t the user be able to take the entire course, regardless of completion rate? It seems it’s shutting down once they hit that 80%. The LMS team is telling me it’s most likely a setting in my captivate file. But it’s not happening to everyone taking it, just a handful of users. Any thoughts?