Sorry about that! It should work now.
We had some issues (and wondering if Gmail is having issues) with emails today. We rolled a fix that increased token expiration and currently looking our email provider if there are things we can do to speed it up.
I think it's Gmail having issues since our login emails sent to Gmail and GSuite arrived late as well. It's been like 7-10min delay, even though our mail delivery system said that the email was delivered.
Alas, the e-mail sign up seems to take a while to send the registration link e-mail. When I got the e-mail after maybe 5-10 minutes of waiting, the sign up link had already expired. :( It says "Verification code expired. Please request a new one." I did, but the same thing happened.