Acumatica Grid Loses rows on refresh

POReceipt has two key fields: ReceiptType and ReceiptNumber. Modify your PXSelect statement to have two fields.

You can find description of key fields in Acumatica source code:

	public partial class POReceipt : PX.Data.IBqlTable, PX.Data.EP.IAssign
	{
		#region Keys
		public class PK : PrimaryKeyOf<POReceipt>.By<receiptType, receiptNbr>
		{
			public static POReceipt Find(PXGraph graph, string receiptType, string receiptNbr) => FindBy(graph, receiptType, receiptNbr);
		}