The new marker has updated its location but old marker not remove in ionic native google map

Ionic Framework
1

The marker is updating to new position and set a new marker but problem with old position marker not remove. marker.remove() not work under this if condition. How I remove old marker? any solution please. here is my code =>

loadMap() {

this.map = GoogleMaps.create('map_canvas', {
  controls: {
    myLocationButton : true,
    myLocation : true
  },
  camera: {
    target: {
      lat: this.latitude, lng: this.longitude
    },
    zoom: 18,
    tilt: 30
  },
});

this.map.addMarker({
  position: { lat: this.latitude, lng: this.longitude },
  draggable: true,
  disableAutoPan: true,
  icon: 'blue',
  title: 'Avirup'
}).then((marker: Marker) => {
  marker.showInfoWindow();

const subscription = this.geolocation.watchPosition().subscribe(position => {
  let geoposition = (position as Geoposition);
  let latitude = geoposition.coords.latitude;
  let longitude = geoposition.coords.longitude;
  let marker : Marker
    marker = this.map.addMarkerSync({
    position: { lat: latitude, lng: longitude },
    draggable: true,
    disableAutoPan: true,
    icon: { url: './assets/image/addresspin.png' ,
    size: {
        width: 30 ,
        height: 30
    }},
    title: 'Move'
  })
  marker.showInfoWindow();
   if(marker.getPosition().lat == latitude && marker.getPosition().lng == longitude){
    marker.remove()
  }
})

}