The documentation for “Get User Info” (https://auth0.com/docs/api/authentication?shell#get-user-info) states:
This endpoint will work only if
openidwas granted as a scope for the Access Token.
And the example response implies you will get the user’s full profile. In fact, you only get sub. Additional scopes are necessary to get the full profile (e.g., scope: "openid email").
I’m new to the platform (and somewhat new to OAuth2), and this took me about 2 hours to figure out.
Hopefully this can help get the documentation improved!