ember-cli-mirage trying to stub auth0 (external) URL

I am working on a new Ember.js project and using ember-cli-mirage to stub out my requests. The project is going to use ember-simple-auth and Auth0 for user authentication. I began implementing them in my project, but I'm getting a weird error in the console when I try to sign up with my Google account using the Auth0 login modal:

Your Ember app tried to GET 'https://(my auth0 domain).auth0.com/userinfo',
but there was no route defined to handle this request.
Define a route that matches this path in your
mirage/config.js file. Did you forget to add your namespace?

(my auth0 domain redacted above)

I have no idea why Mirage would be trying to stub out a request to an external URL. I was reading the Mirage docs and tried using this.passthrough() in my mirage/config.js file so Mirage would make a real request, but that seems to have had no effect (I'm guessing it only explicitly applies to routes within a namespace defined in the config file).

Can anyone help me understand why this is happening and how to stop Mirage from doing it? Thank you!