C# List to DataTable extension method not retrieving properties

I want to convert a ObservableCollection of type KNMOLijst to a DataTable. I found a extension method for it, but it is not retrieving my properties?

Extension method:

public static class ListToDataTable
    {
        public static DataTable ToDataTable<T>(this IList<T> items)
        {
            DataTable dataTable = new DataTable(typeof(T).Name);

            //Get all the properties
            PropertyInfo[] Props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);

            foreach (PropertyInfo prop in Props)
            {
                //Defining type of data column gives proper data table 
                var type = (prop.PropertyType.IsGenericType && prop.PropertyType.GetGenericTypeDefinition() == typeof(Nullable<>) ? Nullable.GetUnderlyingType(prop.PropertyType) : prop.PropertyType);
                //Setting column names as Property names
                dataTable.Columns.Add(prop.Name, type);
            }
            foreach (T item in items)
            {
                var values = new object[Props.Length];
                for (int i = 0; i < Props.Length; i++)
                {
                    //inserting property values to datatable rows
                    values[i] = Props[i].GetValue(item, null);
                }
                dataTable.Rows.Add(values);
            }
            //put a breakpoint here and check datatable
            return dataTable;
        }
    }

The peace of code below is not retrieving any properties, I also tried to include the nonpublic members in the bindingflags, but that didn't seem to work for me

//Get all the properties
PropertyInfo[] Props = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance);

This is the type KNMOLijst it receives:

   public class KNMOLijst
        {
            public string VoorLetters { get; set; }

            public string Voornaam { get; set; }

            public string TussenVoegsel { get; set; }

            public string Achternaam { get; set; }

            public string Geslacht { get; set; }

            public DateTime GeboorteDatum { get; set; }

            public string InstrumentNaam { get; set; }

            public KNMOLijst()
            {

            }
        }

I made sure that the properties were public.

This is the list that the extension method receives.

generatedList.Add(new KNMOLijst()
                {
                    VoorLetters = (string)(row["VoorLetters"]),
                    Voornaam = (string)(row["Voornaam"]),
                    TussenVoegsel = (string)(row["TussenVoegsel"]),
                    Achternaam = (string)row["Achternaam"],
                    Geslacht = (string)row["Geslacht"],
                    GeboorteDatum = (DateTime)row["GeboorteDatum"],
                    InstrumentNaam = (string)row["InstrumentNaam"]
                });

Why is it not able to get the properties of my list?