In a site where reCAPTCHA works fine on login and registration, using either v2 Invisible or v2 Checkbox keys, when comments are enabled on a blog post we see this:

And the html includes a key I don't recognize as one of mine:
etc
while the reCAPTCHA on the login page contains mu public key.
Is there a view with an accidental hard-coded API key or something?
We need to test this in a fresh site from the VS Template.