Replication Callback not received when document updated/added from another phone

[harshOnAndroid]

I am trying to implement just a basic demo. The following code runs. properly on an android device. But when the app ran on iPhone, the replication listener is not working. I am expecting a callback in DocumentReplicationListener. The callback never happens in the case of iPhone.
Following is the code. Only posting relevant code. Everything else is a copy of the example code of this repo.

Future<String> runExample() async {
    // Platform messages may fail, so we use a try/catch PlatformException.
    try {
      database = await Database.initWithName("myDb");
    } on PlatformException {
      return "Error initializing database";
    }

    // Create a query to fetch documents of type SDK.
    var query = QueryBuilder.select([SelectResult.all()])
        .from("getting-started-db");

    // Note wss://10.0.2.2:4984/my-database is for the android simulator on your local machine's couchbase database
    // Create replicators to push and pull changes to and from the cloud.
    ReplicatorConfiguration config =ReplicatorConfiguration(database, "ws://ipAddress/myDb");
    config.replicatorType = ReplicatorType.pushAndPull;
    config.continuous = true;
    // Add authentication.
    config.authenticator = BasicAuthenticator("myDb", "myPassword");

    // Create replicator (make sure to add an instance or static variable named replicator)
    var replicator = Replicator(config);

    replicator.addDocumentReplicationListener((callback){

      var docs = callback.documents.last;
      print("replication listener => ${ jsonDecode(docs.toJson())}");
    });

    // Listen to replicator change events.
    _listenerToken = replicator.addChangeListener((ReplicatorChange event) {
      if (event.status.error != null) {
        print("Error: " + event.status.error);
      }

      print("change == "+event.status.activity.toString());
      print("time == ${new DateTime.now().millisecondsSinceEpoch}");

    });

    // Start replication.
    await replicator.start();

    return "Database and Replicator Started";
  }

[harshOnAndroid]

Turns out, it was a server side mistake.

This solved the problem.