MacBook Pro freezes when using Netflix with Firefox (early 2015, retina, Monterey 12.0.1)

Update Firefox.

Lots of updates in the past two weeks.

Works fine for me.

I'm on version 96.0.2 and just applied an update today (12/22/2021)

Does it work with Safari?

Does it freeze in Safari?

This will help in troubleshooting

I have observed some Firefox 95.* video freezes when viewing Netflix on macOS 11.6.2 on an M1 mini. These did not occur with Firefox 94.0.2, or Safari 15.2 on the same or earlier Big Sur operating system version. I don't watch Netflix on my 16-inch MBP M1 Pro, but I expect Firefox 95.0.2 will misbehave there too with Netflix content.

And I won't either as I am now watching Netflix via my Apple TV 4K+ and a 55-inch UHD HDR TV. 🤓 The only extension in Firefox is Grammarly, and maybe I will remove that to test further. I just noticed that I also had the YouTube High Definition add-on in Firefox, so removing it too.

Interesting. I'm not having Netflix issues on Monterey with Firefox 95.0.2 or Firefox Nightly. Not on my Intel Macs nor my M1 MacBook Air.

Since it does present when booted in to Safe Mode while using Firefox - it would appear Firefox is the source of the issue IMHO.

Does not happen in Safari - hum an idea there ?

Bye the way - Monterey 12.01 is now out dated. As of Monday Dec 13, 2021 - there is an update version 12.1 which brings several big fixes.

 A Time Machine Backup should be performed before attempting the 12.1 update