My video in Captivate 8 is starting slow and choppy

I have an basic 18 MB MP4 video that is supposed to play upon entering a slide. The settings are Progressive Download, Auto Play and using a CoronaSkin player. There is no transition. On the slide itself: On Enter it is set to Continue. I do have closed captions that is available if the learner clicks the CC button in the playbar skin. I am publishing to SWF and SCORM for our LMS.

I have had larger videos play just fine in Captivate 8 in the past. I tried changing the preloader to 50% but that does not help. Can someone help?