@Derek_King it appears that you did everything right and looks good to me but for some reason when the site is being published its loosing the link to the video. Im going to switch this over to the bugs category and maybe someone else can help you with this issue.
It looks like the Background video is playing as expected on this end
If you are seeing other behavior on your end, Derek, can you send me a screen recording of what you see (CloudApp or Quicktime work well)?
Could you also please let me know what browser version you’re using by sending me your information from this page? There should be a small share link when you visit the page which you can send to me.