OK. That's what I suspected. You have the Success/Completion Criteria set to require 100% of slides to be viewed as well as passing the quiz. This setup will often result in the LMS NOT awarding completion because there is just ONE slide somewhere that hasn't been visited by the time the LMS expects.
To be honest, in my own courses I NEVER use both of these ON at the same time. If the module is just providing information (e.g. a Course Intro module with no quiz) THEN I might choose to use the Slide Views as a completion criteria, but then I also have Quiz is Passed turned OFF for that module.
If the module has a quiz and passing that quiz is the main criteria for success, then I ONLY have Quiz is Passed turned on.
I suggest you turn OFF the Slide Views option and test again in your LMS to see what happens.