I am building a site http://www.thaiforum.xyz and even though I can see re-captcga in the registration form and in the Preview it does not show on the live site. Theme Mesocolumn (I get a lot of new unwanted members because of this.)
I have set as demo No activation emails to new users, but anyhow the plugin creates them.
For recpatcha, please make sure that you have put the keys correctly as
far as User notifications are concern, you can no turn it off unless you
modified it in the code. You can only turn off Email verification step.
I hope it clears your confusion.