For instance, https://www.youtube.com/watch?v=J_8mdH20qTQ
Youtube-dl makes the reason pretty obvious: https://www.youtube.com/watch?v=J_8mdH20qTQ [youtube] J_8mdH20qTQ: Downloading webpage [youtube] J_8mdH20qTQ: Extracting video information [youtube] J_8mdH20qTQ: Downloading DASH manifest [download] Destination: Remove cat before flight-J_8mdH20qTQ.f137.mp4 [download] 100% of 58.62MiB in 01:29 [download] Destination: Remove cat before flight-J_8mdH20qTQ.f140.m4a [download] 100% of 2.68MiB in 00:04 [ffmpeg] Merging formats into "Remove cat before flight-J_8mdH20qTQ.mp4" Deleting original file Remove cat before flight-J_8mdH20qTQ.f137.mp4 (pass -k to keep) Deleting original file Remove cat before flight-J_8mdH20qTQ.f140.m4a (pass -k to keep) (e.g., split video/audio) There is definitely something different going on, because firefox can stream this, and chrome (on windows) has no issue as well...
