It should be very easy to get completion when only one slide needs to be viewed according to these settings. I'm thinking there must be some issue with your LMS.
Please test your SCORM zip in SCORM Cloud to see if it completes successfully there with these settings. If the SCORM Cloud LMS doesn't have a problem with the settings then it could be that your particular LMS is set up to require some kind of quiz and points in order to achieve completion.
So then you'd just try adding a button somewhere in the module that the learner is required to click. Set the button to report to the quiz with a score of one point. Then test in your LMS to see if having a scored object is required for completion.