Facebook Videos Records Live Will Not Play in Firefox on MacBook

For the past few weeks, I have been having problems playing certain Facebook videos. It seems to only happen when I try to play a video that was recorded live. I have tried clearing the cache, I've tried a private window, and I've tried safe mode. I still can't get the video to play. However, when I copy and paste the url to Safari, it works fine. I have been able to play "live" videos while they are actually "live"; it's just that they will not load when I try to play them later. I don't have any problems playing videos which have been uploaded to Facebook; only those which were recorded live. The videos just show a circle in the middle as if they are trying to load but nothing else happens. The length of the video does not matter; it happens with short videos as well as long ones. The screenshot image (of a random "live" video I found) I am uploading shows a partial black circle in the center, which is a spinning circle in realtime. I have circled it in red.