Module freezes when being viewed for 2nd time

Hello all,

I created a training module in Storyline.  The test was created external from the module in our LMS.  However if the student wants to resume where they left off and maneuver through module using the navigation buttons, it will freeze after several slides.  However if you close out of the module and reopen it again it works fine.  Any ideas on why its freezing?  FYI, it freezes on different slides for each user.