The DisplayMemberPath is not set after first ItemsSource is set

[capegreg]

I am using a DataGridComboBoxColumn for cell editing. I'm seeing an issue where the DisplayMemberPath does not get set, leaving the cell appearing blank, after the first time the DataGridComboBoxColumn ItemsSource is called, yet the combo box is populated when the cell is in edit mode.

// In my XAML, I have reference to controls
xmlns:controls="using:Microsoft.Toolkit.Uwp.UI.Controls"

// In DataGrid I have the DataGridComboBoxColumn control
<controls:DataGridComboBoxColumn Binding="{Binding VzCategoryId}" DisplayMemberPath="Description" Tag="VzCategory" />

// Code behind

// Collection
private List CategoriesList { get; set; }

// Fill the collection
List cat = new List();
foreach (var item in m) {
cat.Add(new Categories
{
Id = item.Id,
VzCategoryId = item.Id,
Description = item.Description
});
}
CategoriesList = cat;

// Load the DataGrid

// I have experienced issues where DataGrid does not update unless first set to null before loading
VzDataGrid.ItemsSource = null;
VzDataGrid.ItemsSource = VzData;

// Set the DataGridComboBoxColumn ItemsSource. The DisplayMemberPath value is displayed when this is called the first time
New rows are blank for DisplayMemberPath even though CategoriesList includes values for DisplayMemberPath field "Description".

var comboBoxColumn = VzDataGrid.Columns.FirstOrDefault(x => x.Tag?.Equals("VzCategory") == true) as DataGridComboBoxColumn;
if (comboBoxColumn != null)
if (CategoriesList.Count > 0)
comboBoxColumn.ItemsSource = CategoriesList;

[capegreg]

Issue resolved. The binding value was set on the first time the combo was loaded, but zero for new rows.