FocusAsync not working with RadzenDropDown

Radzen.Blazor Components
1

Trying to set focus to a textbox from a RadzenDropBox on selection-change will not work. The textbox will get focus for a moment, then focus returns to the dropdown. It works correctly with a normal "select" dropdown. If I enable the Thread.Sleep, the focus works correctly.

Any ideas?

Chuck

Here is the sample page:

@page "/"
@layout MainLayout
@rendermode InteractiveAuto

<RadzenStack>
    <RadzenLabel>Name</RadzenLabel>
    <select @bind="@SelectedName1" @ref="NameSelectRef" Style="width: 400px;">
        <option value=""></option>
    @foreach (var name in Names)
    {
        <option value="@name">@name</option>
    }
    </select>
    <br />
    <RadzenDropDown TValue="string" Data="@Names" @bind-value="@SelectedName2" @ref="NameRef" Style="width: 400px;" />

    <br/>
    <RadzenLabel>Location</RadzenLabel>
    <RadzenTextBox style="width:100%" @ref="TextBoxRef" />
    @* <input type="text" style="width:100%" @ref="TextBoxInputRef" /> *@

</RadzenStack>

@code {
    private ElementReference NameSelectRef;
    private RadzenDropDown<string> NameRef;
    private RadzenTextBox TextBoxRef;
    private ElementReference TextBoxInputRef;

    public IEnumerable<string> Names;

    public string SelectedName1;
    public string SelectedName2;

    protected override void OnInitialized()
    {
        base.OnInitialized();

        Names = new List<string>() { "Name 1", "Name 2" };
    }

    protected override async Task OnAfterRenderAsync(bool firstRender)
    {
        if (!firstRender)
        {
            //Thread.Sleep(100);
             await TextBoxRef.Element.FocusAsync();
            //await TextBoxInputRef.FocusAsync();
        }
    }
}