If you leave your browser minimized while authenticating for too long, you may see an error that says "400 Bad Request. Your request resulted in an error. Social Transaction expired."
Okta would expire the social transaction if the browser you are authenticating to stays minimized or out of focus (tab not selected) for longer than 10 seconds.
The workaround in this instance is to authenticate again and open the browser back up before 10 seconds have passed.