Affected versions

• Firefox 89.0
• Firefox 90.0b3
• Nightly 91.0a1

Affected platforms

• Windows 10
• Ubuntu 18.04
• macOS 11.3

Steps to reproduce

1. Start Firefox
2. Visit https://edition.cnn.com/videos/
3. From identity panel select Allow Audio and Video
4. Refresh the tab

Expected result

• Video and audio is played without issue.

Actual result

• Video is playing but it's muted.

Regression range

• Not sure if this is a regression, will have to investigate further ASAP if this turns out to be a real bug, Firefox 88.0.1 is also affected.

Additional notes

• Not sure if this is controlled by the website itself, if I use a video from a particular article, this is no longer an issue (eg: https://edition.cnn.com/videos/media/2021/06/02/trump-telegram-big-lie-2020-election-osullivan-vpx.cnn)
• Also I tried with dailymotion and I could not reproduce this issue.

Suggested severity

• If this is a real bug then I would say to mark it with an S3 severity, not knowing how many websites are affected by it.

Setting needinfo on me in order to check for a regression, if this turns out to be a legit issue and not something controlled by the website itself.

Using mozregression I did ended up on 56 Nightly which did not have a way to change the permissions and the behavior was the same, on 55 Nightly I had builds that were unable to play the video at all so I think it's safe to say that this is not a regression and that this is something that cnn controls, I will not close the bug yet though, would be best to have engineers opinion on this.

That is controlled by CNN, we won't make their video muted.