Isolate 环境下 SharedPreferences 数据不能实时同步问题？

AndroidAlarmManager 插件用到了 Isolate 环境，在 Isolate 环境下 refreshStock 函数中的 getShared()拿到的 SharedPreferences 数和上面 saveData()存储的数据不同步，要多次间隔调用的后才会同步到。

cronStock() async {
    _stockCode = _stockCodeController.value.text;
    _growRate = _growRateController.value.text;
    _reduceRate = _reduceRateController.value.text;

    ……

    saveData();
    refreshStock(true);

    await AndroidAlarmManager.periodic(const Duration(seconds: 30), periodicAlarmID, refreshStock, wakeup: true);
}

saveData() async {
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.reload();
    try {
        print('0001 saveData: '+DateTime.now().toString());
        prefs.setString('stock_prefix', stockPrefix);
        prefs.setString('stock_code', _stockCodeController.value.text);
        prefs.setDouble('grow_rate', double.parse(_growRateController.value.text));
        prefs.setDouble('reduce_rate', double.parse(_reduceRateController.value.text));
    } on FormatException catch(e) {

    } catch (e) {
        // No specified type, handles all
    }
}

……

refreshStock([bool isManual = false]) {
    print('0002 refreshStock afterTimer: '+DateTime.now().toString());

    Future<List> stockShared = getShared();
    stockShared.then((List shared) {

        print('isManual: $isManual');
        print('shareData: $shared');

    });
}

Future<List> getShared() async {
    print('getShared');
    SharedPreferences prefs = await SharedPreferences.getInstance();
    prefs.reload();
    return [
        prefs.getString('stock_prefix'),
        prefs.getString('stock_name'),
        prefs.getString('stock_code'),
        prefs.getDouble('grow_rate'),
        prefs.getDouble('reduce_rate'),

        // 当前值
        prefs.getString('stock_price'),
        prefs.getDouble('stock_rate'),
        prefs.getInt('rate_color'),
    ];
}