MVC Core posting a dynamic collection - asp.net

Question

I'm new to MVC and feel like I'm missing something conceptually. I'm trying to create a page where I can submit multiple records at once, dynamically adding and removing records via ajax
I've been trying to follow examples like Steven Sanderson and haacked but whenever I submit the page the collection contains 0 records.
Looking at Fiddler I can see both rows being submitted yet something goes missing.
I've seen references to editor templates and html helpers to make this prettier but these have mostly gone over my head and most of the examples I've found are in old versions of MVC as well.
Model
public class Projection
{
public int ID { get; set; }
[Display(Name = "Project")]
public int ProjectId{ get; set; }
[Display(Name = "Employee")]
public int EmployeeId { get; set; }
public decimal Hours { get; set; }
[DisplayFormat(DataFormatString = "{0:MM/yyyy}", ApplyFormatInEditMode = true)]
public DateTime Month { get; set; }
[Timestamp]
public byte[] RowVersion { get; set; }
public virtual Project Project { get; set; }
public virtual Employee Employee { get; set; }
}
Controller
// GET: Projections/CreateMulti
[HttpGet]
public IActionResult CreateMulti()
{
ViewBag.Index = 0;
ViewData["EmployeeId"] = new SelectList(_context.Employees.Where(e => e.Active).OrderBy(e => e.FullName), "ID", "FullName");
PopulateClientsDropDownList();
PopulateProjectsDropDownList();
return View(new Projection { Month = DateTime.Today.AddMonths(1).AddDays(1 - DateTime.Today.Day) });
}
[HttpGet]
public IActionResult GetNewRow(int index)
{
ViewBag.Index = index;
ViewData["EmployeeId"] = new SelectList(_context.Employees.Where(e => e.Active).OrderBy(e => e.FullName), "ID", "FullName");
PopulateClientsDropDownList();
PopulateProjectsDropDownList();
return PartialView("CreateMultiPartial", new Projection { Month = DateTime.Today.AddMonths(1).AddDays(1 - DateTime.Today.Day) });
}
// POST: Projections/CreateMulti
[HttpPost]
[ValidateAntiForgeryToken]
public IActionResult CreateMulti(ICollection<Projection> ProjectionList)
{
foreach (Projection item in ProjectionList)
{
//do something here
}
return View(ProjectionList);
}
View
#model Test.Models.Projection
#{int Index = 1;
string newRowUrl = #Url.Action("GetNewRow", "Projections", new { index = #Index });}
<form asp-action="CreateMulti">
<table class="table" id="myTable">
<thead>
<tr>
<th>
#Html.DisplayNameFor(model => model.Project.Client)
</th>
<th>
#Html.DisplayNameFor(model => model.Project)
</th>
<th>
#Html.DisplayNameFor(model => model.Employee)
</th>
<th>
#Html.DisplayNameFor(model => model.Month)
</th>
<th>
#Html.DisplayNameFor(model => model.Hours)
</th>
<th></th>
</tr>
</thead>
<tbody>
#{Html.RenderPartial("CreateMultiPartial", Model);}
</tbody>
</table>
<div>Add Another Row</div>
<div>
<input type="submit" value="Submit" class="btn btn-default" />
</div>
</form>
<div>
<a asp-action="Index">Back to List</a>
</div>
#section Scripts {
#{await Html.RenderPartialAsync("_ValidationScriptsPartial");}
<script type="text/javascript">
$("#addNew").click(function () {
event.preventDefault();
$.ajax({
url: $("#addNew").attr("href"),
cache: false,
success: function (html) {
$('#myTable > tbody:last-child').append(html);
indexIterate();
}
});
});
var currentIndex = 1;
function indexIterate() {
var newHref = $("#addNew").attr("href");
var newerHref = newHref.replace(/(?:index=)[0-9]+/i, "index=" + ++currentIndex);
$("#addNew").attr("href", newerHref);
};
});
</script>
}
Fiddler
Projections.Index=0&ClientID=7&Projections%5B0%5D.ProjectId=40&Projections%5B0%5D.EmployeeId=3&Projections%5B0%5D.Month=10%2F2017&Projections%5B0%5D.Hours=1&Projections.Index=1&ClientID=15&Projections%5B1%5D.ProjectId=19&Projections%5B1%5D.EmployeeId=32&Projections%5B1%5D.Month=10%2F2017&Projections%5B1%5D.Hours=1&__RequestVerificationToken=AAA