youtube download still works, just copy the URL and paste it in the paste URL's box (upper right hand corner)
video downloads & plays ok for me.
Something about that I never liked, so I don't use it. JDownloader or thanks to
Germania yt-dlp with the added command --no-warnings works fine.
Still hoping it's a temp YT issue, but if not, it may take time for SF to adjust to it properly.
And I know this video is available in 720 at least, and get this below using the paste URL option