Learners with passing scores not 'complete'

Hi there, I've created a course that has a quiz at the end (just like 99% of all courses) and the LMS tracking is set to mark a learner as 'complete' with a score of 80%.

A small percentage of learners are reporting that despite an 80% or higher score, they are not being marked complete on the LMS. We have tested through SCORM Cloud on all browsers and platforms and are unable to replicate the issue. It works and tracks fine every time.

The client thinks it may be a connectivity issue, but I don't think that would be tracking the score correctly but not the complete status? There doesn't seem to be a definitive way to 'push' the complete status directly through to the LMS in Captivate though, is there?