[fix] #11337 (#11339)

diff --git a/erpnext/selling/doctype/sales_order/sales_order.js b/erpnext/selling/doctype/sales_order/sales_order.js
index 6f70ebe..cfd40df 100644
--- a/erpnext/selling/doctype/sales_order/sales_order.js
+++ b/erpnext/selling/doctype/sales_order/sales_order.js
@@ -40,6 +40,10 @@
 			if(!d.delivery_date) d.delivery_date = frm.doc.delivery_date;
 		});
 		refresh_field("items");
+	},
+
+	onload_post_render: function(frm) {
+		frm.get_field("items").grid.set_multiple_add("item_code", "qty");
 	}
 });