Post-render issue: as notes are falling start of video, live video is not displayed.

Hi, I'm considering purchasing the App, because in the Beta when it was free I had a great experience - however on my second test I am getting an issue after rendering Here is an example of the issue: https://drive.google.com/file/d/1QjATI-neDu2plDLt_BKhWfNmG9nD3gy9/view?usp=sharing As you can see, the video doesn't appear at the start of the video. Any advice would be appreciated! Edit: Additional information: Before rendering, this is not an issue, it works perfectly before rendering (the video does not disappear at the start or end).