title: Cloud Firestore data retrieval fails in 'ng build' version only
body: <p>I'm having a really odd problem with my app, localhost seems to work fine for me. But anytime I use ng-build, or ng-build --prod and deploy to my firebase I have issues with retrieving data. Sometimes it will return data like when i load up on my iPad but more often than not it does not find the data.</p>
  
  <p><a href="https://i.stack.imgur.com/65pSZ.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/65pSZ.jpg" alt="enter image description here"></a></p>
  
  <pre><code> this.as.userObservable()
    .filter(res =&gt; res)
    .subscribe(user =&gt; {
  
      if (this.selectedSeriesSubscription) { this.selectedSeriesSubscription.unsubscribe() }
  
      if (user.selectedSeries) {
        this.getSelectedSeries(user.selectedSeries)
      } else {
        this.fb.settings().valueChanges().take(1)
          .subscribe(settings =&gt; {
            console.log(settings)
            this.getSelectedSeries(settings['defaultSeries'])
          })
      }
    });
  
  
   // SETTINGS - this.fb ^^^
   settings() {
    return this.afs.doc&lt;any&gt;(`global/settings`);
   }
  </code></pre>
  
  <p>That is the code that is firing, it loads the user and user data before this fine though?</p>
  
  <p>I'm using angularfire2, angular 4. Is this only happening because of my build process? </p>
  
  <p>Any ideas would be appreciated. </p>