In another thread you wrote that you publish to Scorm 1.2. The settings in this course seem to be Scorm 2004? Which one is your target version?
Do the users who are not marked as completed in the LMS have a score in the LMS?
You may try to set the score before the status.
… and I agree with Joe. The users may be tempted to close the window from the “Assessment Pass” page. If I’m right to believe that noone would actually not “Record your training” when passed you could just move all the LMS actions from the “Record your training” button to the “Submit Assessment” button.