Audio/Sound Keeps Disappearing for Video

I'm creating a slideshow that includes some videos.  I am setting the video so that I can hear the video in some of the slides.  It plays correctly once and then when I export the whole slideshow the video sound is gone and I only hear the soundtrack audio.  If I close out of Photopia and open back up, I can't even select the audio to adjust it in the video.  In the timeline the audio that goes along with the video completely disappears.  I'm wasting so much time on the audio and this hasn't happened to me in the past.