WPF ListView Live Grouping

I have a listview with dynamic grouping, the code I use to add group descriptions is .

  PropertyGroupDescription groupDescription = new PropertyGroupDescription("CheckSum");
            view = (CollectionView)CollectionViewSource.GetDefaultView(SourceList);
            if (view != null)
            view.GroupDescriptions.Add(groupDescription);

I would like the grouping to be live but have not been able to figure out how to do it. When I try to use ICollectionViewLiveShaping with the same code, it does nothing.

Here is the value converter i am using, it is to convert MD5 values into group names(e.g Group 1, Group 2) etc. It is working fine but after a lot of scrolling top the top and bottom of the list disturbs the order of grouping.

class GroupNameConverter : IValueConverter
    {

        public  int i = 0;
       
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {

        
             if (i <= MainWindow.CheckSums.Count-1)
            {
                i++;

                return "Group " + i.ToString();
            }


            else
            {

                i--;

                return "Group " + i.ToString();

            }

        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            return null;
        }

The grouping is fine at first, but after scrolling up and down the group names get all out of order.

I know the problem could be in the value converter but cant figure out how to fix it. Any help will be greatly appreciated.