firebase-tools: Real time database fails when using Auth emulator

[REQUIRED] Environment info

firebase-tools: 8.14.1

Platform: macOS

[REQUIRED] Test case

In a web app:

  firebase.initializeApp({
    apiKey: "redacted",
    authDomain: "redacted",
    databaseURL: "redacted",
    projectId: "redacted",
    storageBucket: "redacted",
    messagingSenderId: "redacted",
    appId: "redacted",
    measurementId: "redacted",
  })

  authInstance = firebase.auth()
  firestoreInstance = firebase.firestore()
  rtbdInstance = firebase.database()


  authInstance.useEmulator("http://localhost:9099/")
  rtbdInstance.useEmulator("localhost", 9000)
  firestoreInstance.useEmulator("localhost", 8080)

  rtbdInstance.ref().once("value", r => console.log(r.val())) // fails and logs a warning

[REQUIRED] Steps to reproduce

rtbdInstance.ref().once("value", r => console.log(r.val())) // fails and logs a warning

If I don’t use the auth emulator it works fine, fetching my local database

[REQUIRED] Expected behavior

I should get data

[REQUIRED] Actual behavior

No data is returned, and a warning is logged into the dev tools console:

@firebase/database: FIREBASE WARNING: Provided authentication credentials for the app named "[DEFAULT]" are invalid. This usually indicates your app was not initialized correctly. Make sure the "apiKey" and "databaseURL" properties provided to initializeApp() match the values provided for your app at https://console.firebase.google.com/. 

---

My hunch is that the problem could be:

• the database emulator doesn’t know that auth is being emulated and verifies the token against prod
• I’ve got an out of date database emulator? I have i database: downloading firebase-database-emulator-v4.6.0.jar
• there is some specific order the various useEmulator calls have to be made in.