When I followed the instructions shown when selecting "Set up 2-factor authentication", there's a pop-up that says to reload the page. When I did that I was immediately signed out and was unable to log back in without a 2FA key.
Click 'Save', then manually reload this page, scroll down and use the '2FA installation link' to obtain the oath URL for your authenticator.
I did lock myself out, and I had to set up a new account. I hope the developers fix this. Furthermore, I am scared of setting up TOTP now.