Model Being passed as null to the VIew in MVC

WHy does my view Post back an empty List using the MVC code below:

//ProductViewModel
...
public strProductName {get;set;}
public List<ProductsViewModel> lstProducts { get; set; }
...

//Controller
 public ActionResult AddProductQuestions()
        {
            ProductViewModel productviewmodel = new ProductViewModel();
            productviewmodel.lstQuestions = new List<QuestionsViewModel>();

            var query = from q in db.Questions
                        select new QuestionsViewModel()
                        {
                            isSelected = new bool(),
                            intId = q.Id,
                            intIssueId= q.IssueId,
                            strQuestion = q.Question,
                            strResponse = q.Reponse
                        };


            productviewmodel.lstQuestions = query.ToList();
            return View(productviewmodel);
        }


//View
@model MyApp.Models.ProductViewModel

@using (Html.BeginForm("AddProduct","ManageProducts"))
{
...

//This Works and Gets the right Information from the Model when Posted

<div class="form-group">
            @Html.LabelFor(model => model.strProductName, htmlAttributes: new { @class = "control-label col-md-2" })<div class="col-md-10">
                @Html.EditorFor(model => model.strProductName, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.strProductName, "", new { @class = "text-danger" })</div></div>
...


//This Doesn't Post back it always comes back with Null
 @foreach (var item in Model.lstQuestions)
                        {
                            //var questionsCount = Model.lstQuestions.Count();

                            <tr><td>@Html.EditorFor(modelItem =>item.isSelected)</td><td>
                                    @item.intId</td><td>

                                    @item.intIssueId
                                </td><td>

                                    @item.strQuestion
                    </td><td>
                                    @Html.ActionLink("Edit", "Edit", new { id = item.intId }) |
                                    @Html.ActionLink("Details", "Details", new { id = item.intId }) |
                                    @Html.ActionLink("Delete", "Delete", new { id = item.intId })</td></tr>

}

..

Thanks!