It's every video. I tried to play the one you posted, below is what happened (on Chrome). That's odd, though, because I haven't had this issue with Chrome. I tried it in Chrome, Edge, Firefox and even IE. IE never displays Tweets properly, the video played in all other browsers. Then, I tried it in Chrome again, and it played. So I don't know what would cause that. It didn't play the first time I tried it, then it did play in a new tab of the same browser the second time I tried it.
I forgot to mention... the browsers that some of my members are using, are various. So it's not one specific browser but the most recent incident that was reported was Edge.