refresh wheel shows as video progresses as we view mp4 of our modules

My Company using Captivate 8 (just upgraded from 5.5)  As we preview our videos in the browser or publish as MP4 we are getting a little refresh circle appearing as we move from one slide to another.  This is happening on quite a few of our new videos but never happened before...  These do not display in Captivate at all - just on playback - any advice