Background fetch not simulating automatically

In my app, I have installed background fetch plugin that call every 15 mins or some more time interval and do some tasks.
In my app, I have configure this plugin and in promise of configure method, in this method I have scheduled local notification for current day.
Now when i tried to simulate background fetch manually from Xcode Debug menu, It will run this configure method and scheduled local notification for current day. But, when i put the device beside me and do other stuffs on that device, background fetch not simulating automatically at some time interval. Nothing happens and my local notification method won’t call.
Can any one please help me ASAP, what is the issue?

We have tested both ionic-3 and ionic-4 latest
My testing device is iPad (iOS 13.3).
Below is my code for this issue :-

=> This method is called from constructor
this.platform.ready().then(this.onDeviceReady.bind(this));

=> After device ready, this method will call
onDeviceReady() {
this.backgroundMode.enable();

this.backgroundMode.on('activate').subscribe(() => {
  console.log('bg mode active');

  this.backgroundFetch.status().then(res => {
    console.log('status res', res);
  }).catch(err => {
    console.log('status err', err);
  });
});

const config: BackgroundFetchConfig = {
  stopOnTerminate: false
};

this.backgroundFetch.configure(config).then(async () => {
  console.log('call bg fetch');
  this.fetchNotificationData();
  this.backgroundFetch.finish();
}).catch(e => console.log('Error initializing background fetch', e));

}

=> This is method for local notification, called from background fetch configure promise
fetchNotificationData() {
const arrDate = [
‘2020-01-09 04:30:00’,
‘2020-01-09 05:30:00’,
‘2020-01-09 06:30:00’,
‘2020-01-09 07:30:00’,
‘2020-01-09 08:30:00’,
‘2020-01-09 09:30:00’,
‘2020-01-09 10:30:00’,
‘2020-01-09 11:30:00’,
‘2020-01-09 12:30:00’,
‘2020-01-09 13:30:00’,
‘2020-01-09 14:30:00’,
‘2020-01-09 16:00:00’,
];
const arr: ILocalNotification[ ] = [ ];
let cnt = 0;

arrDate.forEach(element => {
  cnt++;
  const dt = new Date(element.replace(' ', 'T'));

  arr.push({
    id: cnt,
    title: 'MCNL',
    text: 'Het is tijd voor uw gezondheidsvragen!',
    trigger: { at: dt },
    vibrate: true,
    wakeup: true,
    led: 'FF0000',
    foreground: true
  });
  console.log('local notfication trigger date -', cnt, dt);
});
console.log('arr', JSON.stringify(arr));
this.localNotifications.schedule(arr);

}