Audio fades in on imported videos

On all of my Captivate Projects, I insert freestanding demo videos into a blank slide following a simple demo slide with music and or voice narration. On the video embed slide, how do I get the audio that's part of the embedded mp4 I've imported from a Camtasia Project to start playing at full volume from the start of the autoplay? The mp4s are all fine, as separate objects. No volume issues. As are the Camtasia projects, the audio plays normally. But after I use Media (dropdown), Insert Video from File Path, and publish to HTML5 and load into my LMS, every single video has a muted or lowered volume level consistently across all my work. This seems more like a setting than a bug. But I saw nothing in the help files or forums.