I am relatively new to Rush. Created a great video recently doing exactly what I am doing now, so I don't know why there is an issue. I am working on a Macbook Pro with macOS High Sierra. I import my Mp4 videos from my iphone onto my laptop and then import them into Rush to use.
There keeps being a LAG with my voice compared to the video!!! I have pulled it off and re-imported, same thing. When i watch the vidoe on my mac - everything is ok, no lag.