fix: Sample qty validation fix in purchase receipt (#18419)

Co-authored-by: Suraj Shetty <surajshetty3416@gmail.com>
diff --git a/erpnext/stock/doctype/purchase_receipt/purchase_receipt.js b/erpnext/stock/doctype/purchase_receipt/purchase_receipt.js
index a2d3e75..7da648a 100644
--- a/erpnext/stock/doctype/purchase_receipt/purchase_receipt.js
+++ b/erpnext/stock/doctype/purchase_receipt/purchase_receipt.js
@@ -264,8 +264,12 @@
 		var d = locals[cdt][cdn];
 		frappe.db.get_value('Item', {name: d.item_code}, 'sample_quantity', (r) => {
 			frappe.model.set_value(cdt, cdn, "sample_quantity", r.sample_quantity);
+			validate_sample_quantity(frm, cdt, cdn);
 		});
 	},
+	qty: function(frm, cdt, cdn) {
+		validate_sample_quantity(frm, cdt, cdn);
+	},
 	sample_quantity: function(frm, cdt, cdn) {
 		validate_sample_quantity(frm, cdt, cdn);
 	},
@@ -283,7 +287,7 @@
 
 var validate_sample_quantity = function(frm, cdt, cdn) {
 	var d = locals[cdt][cdn];
-	if (d.sample_quantity) {
+	if (d.sample_quantity && d.qty) {
 		frappe.call({
 			method: 'erpnext.stock.doctype.stock_entry.stock_entry.validate_sample_quantity',
 			args: {