Problem with video in HTML5 output

Hi, I have this course that I'm building. I need to insert multiple videos. 1 per slide. I manage to insert the videos in .mp4 and when I export to HTML5 output, the first video is working well. Then all other videos does not work. I just hear the sound but can't see the video. Also, if I go back to the first video that was working, it does not show up again, but I can hear the audio.

As soon as you have more than 1 video in the project, the first one works well the first time you see it, then if you go back you only hear the audio, not the images. All other video in the project does not show up but we can still hear the audio.

I'm using the latest version of Captivate 6, output to HTML5.

Thanks!