GUI doesn't update while running

Question

I have a code that connects to the server and get's from it a list of contacts. Iv'e been trying to get it using this function.

        public async Task<List<Contact>> GetContactsAsync()
        {
            try
            {
                // Send the GET_CONTACTS_COMMAND to the server
                await comm.SendMessageAsync(JsonConvert.SerializeObject("GET_CONTACTS"));

                // Wait for and handle the server's response
                string contactsResponse = await comm.ReceiveMessageAsync();

                // Process the server's response
                if (!string.IsNullOrEmpty(contactsResponse))
                {
                    // Parse the response to get the list of contacts
                    List<Contact> contacts = JsonConvert.DeserializeObject<List<Contact>>(contactsResponse);
                    return contacts;
                }
                else
                {
                    MessageBox.Show("Failed to fetch contacts from the server");
                    return null; // or throw an exception
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error during contact loading: {ex.Message}");
                return null; // or throw an exception
            }
        }

This is where I call it

        public async Task LoadChat()
        {
            if (Chats == null)
            {
                Chats = new ObservableCollection<ChatListData>();
                List<Contact> contacts = await GetContactsAsync();
                MessageBox.Show("did");
                Chats.Add(new ChatListData(contacts.ElementAt(0).Username, new Uri("/assets/5.jpg", UriKind.RelativeOrAbsolute), "hello", DateTime.Now, false));
                OnPropertyChanged("Chats");
            }
        }

this is the decleration of Chats

public ObservableCollection<ChatListData> Chats { get; set; }

        public virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }

this is the constructor and the init function

        public ViewModel(Communicator communicator) 
        {
            comm = communicator;
            Initialize();
            LoadChatConversation();
            LoadStatusThumbs();
        }


        private void Initialize()
        {
            try
            {
                {
                    if (comm == null)
                    {
                        comm = new Communicator();
                        _ = comm.ConnectToServerAsync();
                    }
                }
                _ = LoadChat();
                //await comm.ConnectToServerAsync();
            }
            catch (Exception ex)
            {
                MessageBox.Show($"Error during initialization: {ex.Message}");
            }
        }

I've tried to run the loadChat that way (to check if the problem might be with the getContacts functions, but it won't work.

        public async Task LoadChat()
        {
            if (Chats == null)
            {
                Chats = new ObservableCollection<ChatListData>();
                Chats.Add(new ChatListData("shelly", new Uri("/assets/5.jpg", UriKind.RelativeOrAbsolute), "hello", DateTime.Now, false));
                OnPropertyChanged("Chats");
            }
        }

this is the relevant xaml

                <ItemsControl
                ItemsSource="{Binding Chats}" 
                ItemTemplate="{StaticResource ChatButtonItemTemplate}"
                Padding="0,15">
                    <ItemsControl.DataContext>
                        <viewmodels:ViewModel/>
                    </ItemsControl.DataContext>
                </ItemsControl>