How can I make my external Video play properly in my published captivate Project?

I have a Problem with using an external Video in my captivate Project.

I imported an mp4-Video (Intro created with Adobe After Effects, just 3sec long) in my captivate Project and also built an Outro in Captivate (Background with Text that is faded in and out). When I start the preview, everything is fine but when I publish my Project and watch the mp4-Video that Captivate produced, there is always the same mistake occuring.

The intro sequence at the beginning isn´t starting the right way, sometimes in the middle of the Intro sequence. It´s different with every Publishing workflow I start, it´s always beginning at another Point, but never from the Beginning of the Intro sequence. The same Problem I have with the Outro at the end of the captivate Video, it´s not playing properly.

I don´t know what to do or what the error could be and I would be very happy if someone could help me with this Problem.

Thank you very much,

Melissa