Blazor Radio Buttons Binding - test it here - https://blazorfiddle.com/s/3b18q1ix OR https://blazorrepl.com/repl/GYkiPqED26m9cBlb33

sample.cshtml

@foreach (var item in new string[] { "AspNetCore","AspNet","SomeJsThingWhatever"})
{
<div>
  <input type="radio" name="technology" id="@item" value="@item" @onchange="RadioSelection" checked=@(RadioValue.Equals(item,StringComparison.OrdinalIgnoreCase)) />
  <label for="@item">@item</label>
</div>
}
<div>
  <label>Selected Value is @RadioValue</label>
</div>
@code
{
  string RadioValue = "aspnetcore";
  void RadioSelection(ChangeEventArgs args)
  {
    RadioValue = args.Value.ToString();
  }
}