SL 360: Published content as video has an empty long ending
I have a strange artifact happening. I have imported a video in my SL course and use animated objects on top of it. Then I export everything as a mp4 file from the Storyline.
My course has 3 slides: Intro slide with a voice over (no video), Second slide with a video and animation, Final slide with a voice over (no video).
My original video is, say 39 sec. When I publish my complete project as an mp4 file - I get an empty "tail" added of somewhat 40-50 sec more : the output file continues playing empty time, while staying on my Final slide -- nothing happens, it is just an empty "tail" added to my project.
My original video, which I used, is shorter than the whole mp4 output, so it cannot be because of the video I am using.
How to publish in mp4 so that published file ends exactly where my timeline ends on the Final slide?
You can see in the screenshot that the final slide does not have any objects that "live" beyond its end.