Why do I get "Ajax authorization fails" in my tests

I am following the ember tutorials, and specifically I'm on services.

I am 99.9% certain that I have the exact code in place -- I am copying by hand, because I believe that helps me absorb it more completely, but if anything fails I start using a diff checker to see if I made a typo. To my knowledge, no typos.

The App I have written performs identically to the screen shots in the tutorials, and the only error I get is a lint error for having a test that doesn't have an assert in it (yet).

Prior to this unit, all other tests have passed as well. But now I am getting failed tests that previously passed. They appear to all stem from the stubbed call to the map service failing. The first test that fails is integration/component/rental-listing-test.js:

hooks.beforeEach(function() {
  this.rental = {
    image: 'fake.png',
    title: 'test-title',
    owner: 'test-owner',
    type: 'test-type',
    city: 'test-city',
    bedrooms: 3
  };
});
test('should display rental details', async function(assert) {
  await render(hbs``);
  assert.equal(this.element.querySelector('.listing h3').textContent.trim(), 'test-title', 'Title: test-title');
  assert.equal(this.element.querySelector('.listing .owner').textContent.trim(), 'Owner: test-owner', 'Owner: test-owner');
});

If I remove the new line from rental-listing.hbs ( ), thus preventing the map from being used, these tests once again pass (though the new tests for the component using the service have issues).

So either I am doing something wrong that I can't find, or else the fine folk at emberjs.com have not provided complete information in this tutorial. Do I need to somehow stub the map service? that appears in the .hbs file for the above test to pass? If so, why do you think they failed to mention this?