I had a look at this and for some reason the editor doesn’t like the recorded video encoding. It is possible that it is using variable frame rate (VFR) and our editor has trouble seeking frames.
Can you tell me how you captured the footage?
I was able to get the video to render normally by re-encoding the video using FFmpeg:
ffmpeg -i input.mp4 -c:v libx264 -crf 18 -preset slow -c:a copy output.mp4
The new videos work fine. I can post test links if you wish or send you a DM.
We have an ingestion service in the works which will normalize footage recorded on mobiles and web cams. These devices tend to have a wide array of encoding features and standardizing everything before editing will make things more reliable.