When trying to Sign Up for an account at meta.discourse.org, I found I was unable to enter my email address, either by directly typing it into the email field, or selecting one of the various email addresses that pre-populated a select menu from my 1Password browser extension.
It looks like Firefox Relay is the issue. When “Show Relay icon in email fields on websites” was set to the ON position, the email field expanded and would not accept an entry. By turning that setting OFF, and after a refresh of the page, I was able to enter my email and successfully Sign Up for an account.
I spun up a private Discourse server to test it there and found the same thing happened. I would upload the video I made, but as a new user, I don’t have that privilege yet.
I’m on Firefox Developer Edition 96.0b5, for the Mac. I also tested it by disabling my 1PW extension, but that had no effect. Only when I disabled Relay, was I able to enter data in the email field. For the heck of it…I also looked to see if either Chrome or Safari were having any sort of issues like this…and they were not.