UI not refreshing in WPF C# project c#

Question

I'm trying to make a BubbleSort visualizer in a WPF project and every time I perform a swap the UI is supposed to refresh becouse of this code

        public ObservableCollection<MyDataObject> Items
        {
            get { return _items; }
            set
            {
                _items = value;
                OnPropertyChanged(nameof(Items));
            }
        }

Here is the full MainViewModel class

using SaleWPF;
using SaleWPF.FrameWork;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Threading;
using System.Windows.Input;
using System.Threading.Tasks;
using System.Windows;
namespace SortVisualizer
{


    public class MainViewModel : BaseNotification, INotifyPropertyChanged
    {
        public ICommand SortCommand { get; set; }
        public MainViewModel()
        {
            // Inizializza la collezione di oggetti con i dati che devono essere visualizzati
            Items = new ObservableCollection<MyDataObject>
        {
            new MyDataObject { Name = "Nome 1", Value = "Valore 1", Altezza = 30 },
            new MyDataObject { Name = "Nome 2", Value = "Valore 2" ,Altezza = 40},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 50},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 60},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 70},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 80},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 90},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 100},
            new MyDataObject { Name = "Nome 3", Value = "Valore 3" , Altezza = 110},
        };

            // Imposta il titolo della vista
            Title = "Esempio di StackPanel con Binding";
            SortCommand = new RelayCommand(Sort);
        }

        public event PropertyChangedEventHandler PropertyChanged;

        protected void OnPropertyChanged(string propertyName)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

        private string _title;
        public string Title
        {
            get { return _title; }
            set
            {
                _title = value;
                OnPropertyChanged(nameof(Title));
            }
        }

        private ObservableCollection<MyDataObject> _items;
        public ObservableCollection<MyDataObject> Items
        {
            get { return _items; }
            set
            {
                _items = value;
                OnPropertyChanged(nameof(Items));
            }
        }

        public async void Sort()
        {
            bool flag = true;
            int count = 0;
            for (int i = 1; (i <= (Items.Count - 1)) && flag; i++)
            {
                flag = false;
                for (int j = 0; j < (Items.Count - 1); j++)
                {
                    count = count + 1;
                    if (Items[j + 1].Altezza > Items[j].Altezza)
                    {
                        var temp = Items[j];
                        Items[j] = Items[j + 1];
                        Items[j + 1] = temp;
                        flag = true;
                    }
                }
            }
        }


        public class MyDataObject
        {
            public string Name { get; set; }
            public string Value { get; set; }
            public int Altezza { get; set; }
        }
    }
}

And this is the full XAML code

<Window x:Class="SortVisualizer.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:SortVisualizer"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Window.Resources>
        <local:MainViewModel x:Key="ViewModel"/>
    </Window.Resources>

    <Grid DataContext="{StaticResource ViewModel}">
        <StackPanel Height="434" VerticalAlignment="Top">
            <Button Command="{Binding SortCommand}" Content="Sorta"></Button>
            <TextBlock Text="{Binding Title}"></TextBlock>
            <ItemsControl ItemsSource="{Binding Items}">
                <ItemsControl.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <Rectangle Width="{Binding Altezza}" Fill="Black" Height="10">
                                <Rectangle.RenderTransform>
                                    <TranslateTransform X="10" />
                                </Rectangle.RenderTransform>
                            </Rectangle>
                        </StackPanel>
                    </DataTemplate>
                </ItemsControl.ItemTemplate>
            </ItemsControl>
        </StackPanel>
    </Grid>
</Window>

The sort works but the page refreshed at the end only

I tried to insert a Thread.Sleep inside the bubble sort code but there is no difference. I even tried to insert this line of code inside of the bubble sort

Title = Title+"i";

so that the propriety title will make the page refresh but it did not work either.