Xamarin Forms ListView не обновляется из ObservableCollection

ListView моего файла XAML заполняется ViewModel, у которого есть ObservableCollection из службы, но ListView не отображает информацию. Я уже проверяю, что служба возвращает верную информацию.

Это код моего XML-файла:

<?xml version = "1.0" encoding = "utf-8" ?>
<ContentPage xmlns = "http://xamarin.com/schemas/2014/forms"
             xmlns:x = "http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class = "XAMLUnit1.Views.NetflixRoulettePage" Title = "Movie">
    <ContentPage.Content>
         <StackLayout>
         <AbsoluteLayout>
                <BoxView Color = "Gray"  AbsoluteLayout.LayoutFlags = "All" AbsoluteLayout.LayoutBounds = "0,0,1,1"></BoxView>
                <SearchBar x:Name = "searchBar"
                           Placeholder = "Search By Actor's name" 
                           PlaceholderColor = "White"
                           AbsoluteLayout.LayoutFlags = "All"
                           AbsoluteLayout.LayoutBounds = "0.1,0.1,1,1"  SearchCommand = "{Binding SearchMovieCommand}" ></SearchBar>
            </AbsoluteLayout>

       <ListView  x:Name = "ListOfMovies"  
            ItemsSource = "{ Binding MovieList}" >
            <ListView.ItemTemplate>
                    <DataTemplate>
                        <ViewCell>
                            <StackLayout>
                                <ImageCell 
                                        ImageSource = "{Binding poster_path, StringFormat='https://image.tmdb.org/t/p/w500{0}'}">
                                </ImageCell>
                                    <StackLayout Orientation = "Horizontal">
                                    <TextCell Detail = "{Binding title}"></TextCell>
                                    <TextCell Detail = "{Binding release_date}"></TextCell>
                                </StackLayout>
                            </StackLayout>
                        </ViewCell>
                </DataTemplate>
            </ListView.ItemTemplate>
        </ListView>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

Это ViewModel, который вызывает службу и использует ее ObservableCollection в качестве ItemsSource для ListView:

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;
using Xamarin.Forms;
using XAMLUnit1.Models;
using XAMLUnit1.ServiceImpl;
using XAMLUnit1.Services;

namespace XAMLUnit1.ViewModels
{
  public  class MovieRouletteViewModel
    {
        IMovieService service;
        public ObservableCollection<Movie> MovieList { get; set; }
        public ICommand SearchMovieCommand { get; set; }
        public MovieRouletteViewModel()
        {
            service = new MovieServiceFinder();
            SearchMovieCommand = new Command(GetMovies);
        }

        private void  GetMovies()
        { var list= service.GetMovies("");
            MovieList = list;

        }

    }
}




public partial class NetflixRoulettePage : ContentPage
    {
        MovieRouletteViewModel viewModel;
        public NetflixRoulettePage()
        {
            InitializeComponent();
            viewModel = new MovieRouletteViewModel();
            BindingContext = viewModel;


        }



        private void SearchBar_TextChanged(object sender, TextChangedEventArgs e)
        {
        }
    }