Diễn đàn hỗ trợ Firefox

Trying to play video included in Amazon Prime subscription. I received a warning from Amazon about 2 weeks ago that After Dec 6 I would need the latest Firefox update. I updated. Now as shortly after video starts to lord, I get a message in a box that says I need to upgrade Firefox to play this video. I have checked the "about Firefox" tab and it says I am up to date. I am running 91.4.0esr and checkbox says I am up to date. ????

My Firefox change automatic change language. When restart firefox looks ok but after sometime automatic change launguage. Please check attached screenshot. I am using Mac book pro 13in version and other thing attached.