Muted video in firefox doesn't autoplay

Hello,

Our client wants a video looping on the background, this works in most browsers with the autoplay loop and mute attributes on the stream tag, but not in firefox. It seems the think your attached script doesn’t mute things.
If I try it locally on a page with just the embed you provide, I see the following in the console:

Autoplay is only allowed when approved by the user, the site is activated by the user, or media is muted. r4xu.fla9.latest.js:1:134474

Is there anyway you could fix this? Thanks!