Ember.js Acceptance Testing not waiting for asynchronous data operations

When using the Emberfire (Firebase) adapter, I'm getting various errors that indicate the tests are not waiting for data operations to complete.

eg: Error: Assertion Failed: You can only unload a record which is not inFlight. when I try to create, check, and then delete a record

Also:

FIREBASE WARNING: Exception was thrown by user callback. Error: Called stop() outside of a test context at Object.extend.stop (http://localhost:4200/assets/test-support.js:3000:10) at exports.default._emberTestingAdaptersAdapter.default.extend.asyncStart

These errors do not occur while manually navigating through my app, nor when using the standard ember data adapter.

What is causing these errors and how do I avoid them?