ASP.NET Core Razor Pages Grid EJ2 RemoteSaveAdaptor json not working

This works, thanks!

Here is the complete Razor Pages Code, in case someone is interested:

CSHTML Batch Editing

@page
@model IndexModel
@{
    ViewData["Title"] = "EJ2 Grid Test Batch Edit Mode";
}

<ejs-grid id="Grid" toolbar="@(new List<string>() { "Add","Delete","Update", "Cancel" })">
    <e-data-manager json="@Model.Books.ToArray()" adaptor="RemoteSaveAdaptor" insertUrl="Index?handler=ActionHere" updateUrl="Index?handler=ActionHere" removeUrl="Index?handler=ActionHere" batchUrl="Index?handler=ActionHere"></e-data-manager>

    <e-grid-editSettings allowDeleting="true" allowEditing="true" allowAdding="true" mode="Batch"></e-grid-editSettings>
    <e-grid-columns>
        <e-grid-column field="Id" headerText="Id" textAlign="Right" width="120"></e-grid-column>
        <e-grid-column field="BookName" headerText="Book Name" width="150"></e-grid-column>
        <e-grid-column field="EAN" headerText="EAN" width="130" textAlign="Right"></e-grid-column>
    </e-grid-columns>
</ejs-grid>

CSHTML.cs Code Behind File

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.RazorPages;
using Syncfusion.EJ2.Base;

namespace TheDefinitveGridEJ2.Pages
{
    [IgnoreAntiforgeryToken(Order = 1001)]
    public class IndexModel : PageModel
    {
        public List<Book> Books = new List<Book>();
        public void OnGet()
        {
            bool isEmpty = !Books.Any();
            if(isEmpty)
            {
                GetDataSource();
            }          
        }
       
        public void GetDataSource()
        {
            Books.Add(new Book() { Id = 44, BookName = "Cool", EAN = "4444444444444" });
            Books.Add(new Book() { Id = 55, BookName = "Cool1", EAN = "55555555555" });
            Books.Add(new Book() { Id = 66, BookName = "Cool2", EAN = "66666666666" });
        }

        public IActionResult OnPostActionHere([FromBody]CRUDModel<Book> myObject)
        {
            //  SET BREAKPOINT HERE. CRUD Operations can be made to a MS SQL Database at this place. Take a look at myObject during break, various information can be gathered from myObject.
            return Page();
        }

        public class Book
        {
            public int Id { get; set; }
            public string BookName { get; set; }
            public string EAN { get; set; }
        }
    }
}