Incomplete tracking in courses loaded in Moodle

Greetings everyone! I am having an issue with a course on a Moodle platform.  The course has several activities (including a survey at the end which must be completed to generation completion certification).  I have three SCORM package modules that are loaded into this course. I have the LMS Reporting set to Complete/Incomplete for all three (and all three are published in SCORM 1.2) Of the 20 people who have attempted to take this course, 2 have successfully completed it but 18 have gotten hung up on the first of the three modules I have loaded.  Although they have gone through every slide as required, it is not marking off as complete in the system so they are unable to progress.  (Note: The people who are having difficulty have tried on multiple computers using multiple browsers.) 

Has anyone experienced a similar issue?