Custom View Cell: View not getting updated in case PropertyChanged event

I have a listview which consumes custom view cell.
However View is not getting updated in case of property change event is triggered .
I can see that View Model is getting updated values in case event is triggered but my View is not getting updated.

CustomViewCell.xaml:

  <Label HorizontalTextAlignment="Start"
                                   VerticalTextAlignment="End"
                                   FontSize="16"
                                   FontAttributes="Bold"
                                   LineBreakMode="WordWrap"
                                   Grid.Column="0"
                                   Grid.Row="0"
                                   Text="{Binding TextMain}"
                                   x:Name="MainTitleLabel"/>
  <Label HorizontalTextAlignment="Start"
                                   VerticalTextAlignment="Center"
                                   FontSize="14"
                                   Grid.Column="0"
                                   Grid.Row="1"
                                   Text="{Binding TextDetail}"
                                   x:Name="TextDetailLabel"/>
  <Image VerticalOptions="Center"
                                   HorizontalOptions="EndAndExpand"
                                   HeightRequest="24"
                                   WidthRequest="24"
                                   IsOpaque="True"
                                   Grid.Column="2"
                                   Grid.Row="0"
                                   Grid.RowSpan="2"
                                   Source="{Binding ImageSource}}"
                                   x:Name="ImageSourceLabel"/>

CustomViewCell.xaml.cs:

public CustomViewCell()
{
  InitializeComponent();
}

public static BindableProperty MainTitleProperty = BindableProperty.Create(nameof(MainTitle), typeof(string), typeof(CustomViewCell));
public string MainTitle
{
  get => (string)GetValue(MainTitleProperty);
  set => SetValue(MainTitleProperty, value);
}    

public static BindableProperty TitleDetailProperty = BindableProperty.Create(nameof(TitleDetail), typeof(string), typeof(CustomViewCell));
public string TitleDetail
{
  get => (string)GetValue(TitleDetailProperty);
  set => SetValue(TitleDetailProperty, value);      
}

public static BindableProperty ConnectionImageSourceProperty = BindableProperty.Create(nameof(ConnectionImageSource), typeof(Image), typeof(CustomViewCell));
public Image ConnectionImageSource
{
  get => (Image)GetValue(ConnectionImageSourceProperty);
  set => SetValue(ConnectionImageSourceProperty, value);
}
protected override void OnBindingContextChanged()
{
  MainTitleLabel.Text = MainTitle;
  DetailLabel.Text = TitleDetail;
  ImageSourceLabel.Source = ConnectionImageSource.Source;
  base.OnBindingContextChanged();
}   

CustomViewCellViewModel .cs:

public class CustomViewCellViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected void OnPropertyChanged([CallerMemberName] string propertyName = "") =>
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));

private string _mainTitleText = null;
public string MainTitleText
{
  get { return _mainTitleText; }
  set
  {
    if (_mainTitleText == null || !_mainTitleText.Equals(value))
    {
      _mainTitleText = value;
      OnPropertyChanged("MainTitleText");
    }
  }
}

private string _titleDetailText = null;
public string TitleDetailText
{
  get { return _titleDetailText; }
  set
  {
    if (_titleDetailText == null || !_titleDetailText.Equals(value))
    {
      _titleDetailText = value;
      OnPropertyChanged("TitleDetailText");
    }
  }
}

private string _imageSource = null;
public string ImageSource
{
  get { return _imageSource; }
  set
  {
    if (_imageSource == null || !_imageSource.Equals(value))
    {
      _imageSource = value;
      OnPropertyChanged("ImageSource");
    }
  }
}