How To - Update/Assign Date & Time split field value while importing Sales Order from Shopify to Acumatica using Shopify Connector

Hi Team,

We are working with Shopify connector (build: 21.224) to import Shopify Orders into Acumatica. We have a date field that we want to update with Shopify order created date time. This field is split on the UI as Date and Time part but is a single field only. We tried like below but the field value is not updating. Can you please review below details and suggest the best possible way to do that.

DAC: 

 #region UsrKNSPSBOrderPlacedTimeStamp
        [PXDBDateAndTime(PreserveTime = true)]
        [PXUIField(DisplayName = "Placed Datetime")]
        public DateTime? UsrKNSPSBOrderPlacedTimeStamp { get; set; }
        public abstract class usrKNSPSBOrderPlacedTimeStamp : PX.Data.BQL.BqlDateTime.Field<usrKNSPSBOrderPlacedTimeStamp> { }
        #endregion

Graph:

public class KNSPSBSalesOrderProcessorExt : PXGraphExtension<SPSalesOrderProcessor>
    {
        public static bool IsActive() { return true; }        

        public delegate void MapBucketImportDelegate(SPSalesOrderBucket bucket, IMappedEntity existing);
        [PXOverride]
        public void MapBucketImport(SPSalesOrderBucket bucket, IMappedEntity existing, MapBucketImportDelegate baseMethod)
        {
            baseMethod(bucket, existing);
            MappedOrder obj = bucket.Order;            
            OrderData data = obj.Extern;
            SalesOrder impl = obj.Local;
            DateTime? orderCreatedAt = data.DateCreatedAt;            
            impl.Custom = new PX.Api.ContractBased.Models.CustomField[]
                     {
                            new CustomDateTimeField()
                            {
                                 ViewName = "CurrentDocument",
                                 FieldName = "UsrKNSPSBOrderPlacedTimeStamp",
                                 Value = orderCreatedAt.ValueField()
                            }
                     }.ToList();
        }
    }

Aspx:

<px:PXDateTimeEdit runat="server" ID="CstPXDateTimeEdit1" CommitChanges="True" DataField="UsrKNSPSBOrderPlacedTimeStamp_Date" />
                            <px:PXDateTimeEdit runat="server" ID="PXDateTimeEdit1" EditFormat="g" DisplayFormat="g" TimeMode="True" SuppressLabel="True" CommitChanges="True" DataField="UsrKNSPSBOrderPlacedTimeStamp_Time" />

Thank you in Advance!