Over the last several months I’ve started having a lot of issues with firefox. I’ve been unable to watch videos on certain sites, ones for livestreaming especially, and unable to login on others. Its like the buttons are disconnected or something. I’ll press the login button and nothing will happen.
I’ve had to use chrome, though I’ve recently decided to use edge instead, for livestreaming sports, logging into crunchyroll, and reddit, among others.
Try a useragent switcher and spoof a different browser. See if its the sites you visit are throttling you for using FF. Worth a test.