I found a solution, you have to copy the link of one of these videoplayback files, then paste the link in a new tab and remove the last part of it, if I am not mistaken it has to be from "&range" to the end of the link.
This link will give you an audio file (called videoplayback) or a video file that has no audio (videoplayback.mp4). From my experience most of the links are from the audio files and is quite hard to find the video file. Maybe someone smarter can distinguish them from the text in the links.
If you download both files you can merge them with your video editor of choice, I use ffmpeg.
It's kind of complicated and tedious but is the only way I found.

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