This is a deal breaker for me. I’m trying to leave Chrome, but if Firefox is this broken then we are in big trouble. When logging into a website where the username and password screens are separate (twitter.com for example) the autofill will not prompt to fill in the username. You must manually type the email first. Then on the next screen the autofill option prompts to fill the password. I use Bitwarden. But it was the same for iCloud Passwords.