Nativescript. Mapbox. Typescript + Angular2

Question

I use mapbox in my application. When I navigate on the page, where I use map, all works perfect. After that I tap on one of the markers and I navigate on the next page. But when I click backButton, or call routerExtensions.back() on the next page, I return on the page with map, but map dissapears. I can tap blindly on my map markers and I will navigate on the next page, but I don't see map.

Here is the code of class with map:

export class CarwashListComponent implements OnInit {

    ngOnInit() {
        this.initMap();
    }

    initMap() {
        var _this = this;
        this.mapbox.show({
            accessToken: "pk.eyJ1IjoiaWxqYWdyYWJhcjE0IiwiYSI6ImNpd25laGw2YTAwMTIyeW10ZXM0a3l6M2UifQ.CfGJKVjVzM-lRzko7cP37g",
            mapStyle: "light",
            center: { // optional without a default
                lat: this.cities[0]['coordinates'][1],
                lng: this.cities[0]['coordinates'][0]
              },
            markers: [
                {
                 lat: 52.3732160, 
                 lng: 4.8941680, 
                 title: 'Nice location', 
                 subtitle: 'Really really nice location', 
                 onCalloutTap: function () {
                                 _this.routerExtensions.navigate(["next_page"]))
               }
            ],
            zoomLevel:9.5,
            showUserLocation: "true"
      })
   }
}

What am I doing wrong?