Hey, not sure if related, but in settings (in dev.twitter.com), I changed application type to read only, callback URL to the homepage of my website, and checked “Allow this application to be used to Sign in with Twitter”.
After a few minutes, I went back to my WP dashboard and my account was available for authentication “Authorize new account”. Then I did the “Sign in to twitter” from that link in WP dashboard and I’m back up.
