SyncAdapter- onPerformSync has no internet access

I have a SyncAdapter class that connects to an MQTT broker and publish payload for the server to receive the payload. However, it seems that even though the onPerformSync() method is invoked, the internet access is not there. I thought using SyncAdapter guarantees internet access?

Here is the SyncAdapter Class

public class SyncAdapter extends AbstractThreadedSyncAdapter {
    private static final String TAG = SyncAdapter.class.getSimpleName();
    private MqttHelper mqttHelper;

    public SyncAdapter(Context context, boolean autoInitialize) {
        super(context, autoInitialize);
        mqttHelper = new MqttHelper(getContext());
    }

    public SyncAdapter(Context context, boolean autoInitialize, boolean allowParallelSyncs) {
        super(context, autoInitialize, allowParallelSyncs);
    }
    private boolean isNetworkAvailable() {
        ConnectivityManager connectivityManager
            = (ConnectivityManager) getContext().getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetworkInfo != null && activeNetworkInfo.isConnected();
    }

    @Override
    public void onPerformSync(Account account, Bundle extras, String authority, ContentProviderClient provider, SyncResult syncResult) {
        Log.wtf(TAG, "onPerformSync: ");
        Log.wtf(TAG, "SYNC_EXTRAS_MANUAL: " + extras.getBoolean(ContentResolver.SYNC_EXTRAS_MANUAL));
        Log.wtf(TAG, "SYNC_EXTRAS_EXPEDITED: " + extras.getBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED));

        Log.wtf(TAG, "internte: " + isNetworkAvailable());


        mqttHelper.connect(new IMqttActionListener() {
            @Override
            public void onSuccess(IMqttToken asyncActionToken) {
                Log.wtf(TAG, "onSuccess: ");
                mqttHelper.pub("hello/android", "Finally working via sync adapter praise the lord!!!!");
                // TODO: Get Checkpoints from Realm
                // TODO: publish at once
                // TODO: Disconnect
                mqttHelper.disconnect(new IMqttActionListener() {
                    @Override
                    public void onSuccess(IMqttToken asyncActionToken) {
                        Log.wtf(TAG, "onSuccess: disconnect");
                    }

                    @Override
                    public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                        Log.wtf(TAG, "onFailure: disocnnect");
                    }
                });
            }

            @Override
            public void onFailure(IMqttToken asyncActionToken, Throwable exception) {
                Log.wtf(TAG, "onFailure: ", exception);
            }
        });

    }

    @Override
    public void onSyncCanceled() {
        super.onSyncCanceled();
        Log.wtf(TAG, "sync canceled");
    }
}

And also a snippet of my Android Manifest pertaining to the MqttService and SyncAdapter:

<application
    ...
    <receiver android:name=".LocationPollingReceiver" />
    <service android:name="org.eclipse.paho.android.service.MqttService"
        android:process=":sync"/>
    <service
        android:name=".LocationPollingService"
        android:exported="false"/>
    <service
        android:name=".sync.AuthenticatorService">
        <intent-filter>
            <action android:name="android.accounts.AccountAuthenticator"/>
        </intent-filter>
        <meta-data
            android:name="android.accounts.AccountAuthenticator"
            android:resource="@xml/authenticator" />
    </service>
    <provider
        android:name=".sync.StubProvider"
        android:authorities="proj.com.fyp.provider"
        android:exported="false"
        android:syncable="true"/>
    <service
        android:name=".sync.SyncService"
        android:exported="true"
        android:process=":sync">
        <intent-filter>
            <action android:name="android.content.SyncAdapter"/>
        </intent-filter>
        <meta-data android:name="android.content.SyncAdapter"
            android:resource="@xml/syncadapter" />
    </service>
</application>

Does this have anything to do with invoking the sync manually? like what I did below?

Account mAccount = MainActivity.CreateSyncAccount(context);
Bundle settingsBundle = new Bundle();
settingsBundle.putBoolean(ContentResolver.SYNC_EXTRAS_MANUAL, true);
settingsBundle.putBoolean(ContentResolver.SYNC_EXTRAS_EXPEDITED, true);
//settingsBundle.putBoolean(ContentResolver.SYNC_EXTRAS_FORCE, true);
ContentResolver.requestSync(mAccount, AUTHORITY, settingsBundle);

Even syncing via the Settings->Account->Sync now produced the same result.