Dropdown not showing selected item

I'm pretty new to Blazor/Radzen environment and I know I'm not the sharpest clam in the bucket but I still can't figure this out. In all the sample code I could find it didn't seem like the OnChange event needed to do anything to set the SelectedText other than invoking StateHasChanged

I have a List of Properties, the two important fields are string WAddressDisplay and double PropID.
The Dropdown populates perfectly. I can select the item I want and the OnChange fires perfectly but the selection doesn't show up in the Dropdown selection. I know the item is properly selected because the OnChange returns the correct item.

Here's my HTML for the dropdown

   <RadzenDropDown AllowClear="true" TValue="string"
              Name="pAddress" AllowFiltering="true"
              Change=@(args => OnChange(args, "newAddress")) Class="w-100">

Here is my OnChange

double boundValue = 0;
    void OnChange(object value, string name)
        var str = value is IEnumerable<object> ? string.Join(", ", (IEnumerable<object>)value) : value;
        if (name == "newAddress")
            if (str != null)
                propertyLink = boundValue;
                buttonOKDisabled = false;
                boundValue = 0;
                propertyLink = "";
                buttonOKDisabled = true;

This is my PropertyDTO (abbreviated)

  public class PropertyLookupDto
        public int Id { get; set; }
        public string Town { get; set; } = null!;
        public double PropId { get; set; }
        public string WAddressDisplay { get; set; }

Selecting an item:

Results after selecting an item:

OK button has been enabled and the PropID has been properly selected, it's just the selected text is still blank :frowning:

To set the selection of RadzenDropDownList you should use its Value property. Or @bind-Value if you want RadzenDropDown to update the property too. Check the dropdown demos for further reference: Blazor DropDown component

I added a @bind-Value as suggested and that did clean up my OnChange logic a little so that's great but the Dropdown Selected Item area is still blank. All the logic in the actual code is working perfectly.

I updated the original post with the new code and sample snapshots of the issue.

Let me know if more details might be helpful.
Any suggestions would be greatly appreciated.

What are the values of PropId? Are they unique?