@Chuecaman-0 I just subscribed to a JFF account yesterday and found that the firefox downloader plugin that worked properly before is not working anymore, and apparently it is a general well known restriction that JFF has managed to impose.
searching the internet, there are some paid applications that download, but it is not the full 1080p quality, it does not function optimally, and I don't trust them to pay for the full version
hopefully someone can find a JFf solution ... or otherwise I will have to do a screen capture playing the full video