Display a telerikgrid in blazor on a button click - wont load

I have a blazor component.Im trying to display a test table once a button is clicked like so:

<button id="btnKltClms" class="slikaButton" @onclick="TestClick" hidden="@isBtnKltClmsHidden"></button><div hidden="@isTbResultsHidden"> <TelerikGrid Data="@resultTableData"><GridColumns><GridColumn Field="@nameof(ResultTableRow_Klt_Clms.CompanyName)" Title="חברה" /><GridColumn Field="@nameof(ResultTableRow_Klt_Clms.CompanyNumber)" Title="מספרחברה" /><GridColumn Field="@nameof(ResultTableRow_Klt_Clms.DeliveryNumber)" Title="מספרמשלוח" /><GridColumn Field="@nameof(ResultTableRow_Klt_Clms.RecordedEntriesNumber)" Title="מספררשומותשנקלטו" /><GridColumn Field="@nameof(ResultTableRow_Klt_Clms.ShguimEntriesNumber)" Title="מספררשומותשגויות" /></GridColumns></TelerikGrid> </div>

And thats my code behind file:

       async Task TestClick()       {           resultTableData.Clear();           for (int i = 0; i <= 5; i++)           {               current_Company1 = $"curComp{i}";               current_Company_name1 = $"curCompName{i}";               CURRENT_MISHLOACH1 = $"mishloah{i}";               TOTAL_SHG_D1 = $"totalShg{i}";               await BuildResultTable();           }           StateHasChanged();       }       async Task BuildResultTable()       {           resultTableData.Add(new ResultTableRow_Klt_Clms           {               CompanyName = StringUtil.Reverse(current_Company_name1),               CompanyNumber = current_Company1.ToString(),               DeliveryNumber = CURRENT_MISHLOACH1.ToString(),               RecordedEntriesNumber = (recordarr.Length - 2).ToString(),               ShguimEntriesNumber = TOTAL_SHG_D1.ToString()           });           isTbResultsHidden = false;           isLabelErrorHidden = false;           StateHasChanged();       }

When I check in debug, obviously the list will include 6 items.When table is displayed ( after a button click it will display an empty table

Ive been trying to "play" with signatures , async void, async Task, await, not await, all of that.

Ive been also trying to do this

await InvokeAsync(() => StateHasChanged());

but its clear that something in that logic is beyond my understanding as of now.Any ideas?Thanks !!