Steps to reproduce

1. Open about:config
2. Search for autoplay in the settings
3. Set media.autoplay.default to 1 (”Block Audio”, which is the default)
4. Set media.autoplay.blocking_policy to 2
5. Open a Twitch VOD, for instance https://www.twitch.tv/videos/280106033
6. Try to unmute the video (either by clicking Twitch player’s speaker control button, or by dragging the accompanying volume slider)

What I expect to happen

For the audio to be unmuted.

What happens instead

The audio remains muted, and the volume control/indicator remains in the muted position.

I’m unmotivated to report this to Twitch, as I’m unsure about the precise meaning of media.autoplay.blocking_policy, and I currently don’t use the non-working value for it myself. Feel free to downprioritize this as you see fit, unless the original reporter is still affected. Here’s my downstream report over at Launchpad though, just for reference. (I’ll update it too.)