Those are not live videos
They will restart when you come in or f5 if set to autoplay
They only way to see those together is to have you and others start them together
Or there is players here you can get that will do live all see the same on.
SiTV is free and has live on it, my profile has the info page link to it or inbox me for help.
There is also other players that are not free listed in the directory that will allow you to do "live" of your choosing on them.
Or they have it where only one person has to start the video and then all see the same.