Custom column in Run Service Contract Billing (FS501300) form doesn't dislpay dqata

Hello,

I’m trying to resolve the following issue: custom column added to the grid contains no data.

Here are the details.

I am trying to customize the Run Service Contract Billing (FS501300) form to add Organization ID column into its Contracts grid.

To do that I extended the ContractPeriodToPost DAC for the grid based on the following article: https://blog.zaletskyy.com/post/2020/03/09/post100 .
My extension is as following.

using PX.Data;

using PX.Data.BQL;

using PX.Objects.GL;

namespace PX.Objects.FS

{

    public class ContractPeriodToPostExt : PXCacheExtension<ContractPeriodToPost>

    {

        public static bool IsActive() => true;

        #region UsrCompanyID

        [PXInt]

        [PXUIField(DisplayName = "Organization ID")]

        [PXDBScalar(typeof(Search<Branch.organizationID, Where<Branch.branchID, Equal<ContractPeriodToPost.branchID>>>))]

        public virtual int? UsrCompanyID { get; set; }

        public abstract class usrCompanyID : BqlInt.Field<usrCompanyID> { }

        #endregion

    }

}

Then using Screen Editor, I added UsrCompanyID (Organization ID) control of type NumberEdit to the Grid.
As a result, the Contracts grid now has the Organization ID column, however it doesn’t contain any data.

The grid though successfully displays all the data for all the other columns.

What should I do to display data in the Organization ID column?

Thank you!