I don’t have time to figure out your video but it seems that maybe the preview isn’t working?
the problem is that the video preview does glitching around, most time I have black screen (in video editing were I make key frames) and this makes video editing impossible. and on the end of the video were I want to save the video and render it, it says "There was an error reading media in your project..."
or maybe there is a bug in the new version of LumaFusion (it has only just been released)
no in the previous version I had the same problems (I thought it will be fixed in the new version)
It would also be useful to know what sort of video clips you are using - the source.
I testet it with mp4 and MOV videos, same problem.
i just figured something out. https://www.youtube.com/watch?v=EAAsYY1TgFY there are more details in the video