The produced YT video is at 23.976 fps. There is a black frame at 17,18,32,122, etc. in the video. The appearance of the black frame mathematically here does not make sense and can happen if the produced frame rate is not a multiple of the source. I see this in the past when video is converted with Super.
Example of this is the video is reversed but the 60 fps source is not slowed 0.4 but an arbitrary number is used and produced to 24 fps.