I did some more extensive testing for that video and the problem appears to be the default server for that video. In the chrome extension it was
resulting in network error failure when using the browser to perform the download. Using the coapp to perform the download it simply sat at 0% .
Using Firefox with the browser performing the download it also resulted in a network error failure. The coapp however this time downloaded it.
Back to the chrome extension but this time choosing the other server options and the video manages to download.
In short the default server is the issue, if you choose one of the other server options it will work in chrome.