Firefox - Local videos embedded in article not playing

In firefox, when I read an article that features local videos (those not hosted by Youtube or a Twitch clips) I go to play the video and it just loads forever. No ad plays, nor does the actual video. I am using Firefox 59.0.3 (64-bit). I don’t experience the issue in Chrome or IE. I have an adblocker installed, but I have it waypoint whitelisted. I even disabled the adBlock altogether and the videos still failed to load.

Example article that features videos that won’t play:

I was curious if anyone else has experienced a similar issue?