My firefox installation failed to play any videos. It would load the video forever (longest time was 15 minutes) and never actually play; this persisted on all media sites I tried and was exclusive to firefox (other browsers worked fine). I reinstalled firefox entirely as a last resort. I now cannot sign in with my account to sync any of my browser data.

I use firefox on three places: macOS laptop, windows PC, and mobile phone (ios). When I try to sign in on the windows PC (the new installation), it lets me sign in and then says the sync failed and I need to sign in to sync data. It forces me to verify my sign in every single time. even if I just signed in and hit the sync option, it makes me sign in and verify my account again. It has been an hour of troubleshooting and I'm so goddamn frustrated with this. Never had any issues like this in the eight years I've used FF, but this mess makes me want to switch browsers entirely. IDK what to do.