Bug? Autoplay "Block Audio" is allowing audio, not video.

[helix400]

For live streamed YouTube videos we manage for Sunday church services, I'm seeing some strange behavior.

Firefox is starting these videos with Autoplay: "Block Audio". So far so good. However, when I click play on these live streamed videos, I get audio but not video, it's like I get a frozen thumbnail video image. Stranger, about 5% of the time it works, I get audio AND video.

When I click on the URL bar and select for Autoplay: "Allow Audio and Video", then it all works.

Normal non-live streamed videos aren't showing any strange behavior. Only our live streamed ones.

I've tested this on multiple computers, on any profile, including brand new profiles. I've also tested it on completely different networks in different buildings. I noticed the behavior start up roughly 3 weeks ago.

I'm tempted to submit a bug report, but I'm wondering if anyone else has any insights or ideas to check.