Fixed POItem one to many grid when loading empty PO

prs.desktop/Panels/Products/Reservation Management/JobRequisitionsPanel.xaml

@@ -39,7 +39,7 @@
                                 Click="ReserveStock_Clicked"/>
                         <StackPanel Grid.Column="1" Orientation="Horizontal" x:Name="PurchaseOrderButtons"/>
                         <Button x:Name="AddPOButton" Grid.Column="2" Height="30" FontWeight="DemiBold"
-                                Content="New"
+                                Content="New PO"
                                 BorderBrush="DarkGray" BorderThickness="1.25"
                                 Margin="1,2,0,0"
                                 Padding="13,3"

prs.desktop/Panels/Suppliers/PurchaseOrders/SupplierPurchaseOrderItemOneToMany.cs

@@ -121,8 +121,18 @@ namespace PRSDesktop
                 var data = PageDataHandler?.Invoke(type);
                 if (data is null && type == typeof(PurchaseOrderItem))
                 {
+                    Filter<PurchaseOrderItem> filter;
+                    if (Item.ID == Guid.Empty)
+                    {
+                        filter = new Filter<PurchaseOrderItem>().None();
+                    }
+                    else
+                    {
+                        filter = new Filter<PurchaseOrderItem>(x => x.PurchaseOrderLink.ID).IsEqualTo(Item.ID);
+                    }
+
                     data = new Client<PurchaseOrderItem>().Query(
-                        new Filter<PurchaseOrderItem>(x => x.PurchaseOrderLink.ID).IsEqualTo(Item.ID),
+                        filter,
                         DynamicGridUtils.LoadEditorColumns(DataColumns()),
                         LookupFactory.DefineSort<PurchaseOrderItem>());
                 }