title: Firebase streams fetches data I can't see in the console
body: <p>yeah, I imagine that this sounds pretty strange but maybe some of you have an idea or at least a hint where I could start searching:
  I am building an application with flutter and cloud firestore as the server. I connected my app with the collections in the console, I set up the streams - everything has been working fine and the data arrived fastly to be displayed in the way I wanted it to be.
  Now, since a few days, I was trying to establish a new function that creates new objects in the firestore. For testing purposes I also deleted a few ones which already existed, which brings the objects I see in the console to 3. However, the stream fetches 11, including the ones I deleted manually and a few which have been created successfully via my function but are not even displayed in the console. And seems like they are appearing out of nowhere. I double-checked all the other collections but there is nowhere to hide for these objects.
  And now I don't know what to do. I can't keep on working like this. I will add a bit of code to show I process the data. Maybe someone already experienced this weird behaviour?</p>
  <pre><code>  Widget _fetchAllGroupsAndBuildList(){
      return StreamBuilder&lt;List&lt;Group&gt;&gt;(
          stream: DatabaseService().groups,
          builder: (context, snapshot){
            if(snapshot.hasData)
            {
              allGroups = snapshot.data;
              return _buildAllGroupsList();
            }
            else if(snapshot.hasError){
              print(snapshot.error);
              return Container(child: Text(&quot;Ups, something went wrong.&quot;));
            }else{
              return Container(child: Text(&quot;Ups, something went wrong.&quot;));
            }
          }
      );
    }
  
    Stream&lt;List&lt;Group&gt;&gt; get groups {
      try {
        return groupCollection.snapshots()
            .map(_groupListFromSnapshot);
      } catch (e) {
        print(&quot;Database, getGroups: &quot; + e.toString());
        return null;
      }
    }
  
    final CollectionReference groupCollection = FirebaseFirestore.instance.collection(
        'groups');
  </code></pre>