fix: don't update previous doc on rate change
diff --git a/erpnext/controllers/accounts_controller.py b/erpnext/controllers/accounts_controller.py
index f551133..4ab9e24 100644
--- a/erpnext/controllers/accounts_controller.py
+++ b/erpnext/controllers/accounts_controller.py
@@ -3248,7 +3248,10 @@
 
 	if parent_doctype == "Purchase Order":
 		update_last_purchase_rate(parent, is_submit=1)
-		parent.update_prevdoc_status()
+
+		if any_qty_changed or items_added_or_removed or any_conversion_factor_changed:
+			parent.update_prevdoc_status()
+
 		parent.update_requested_qty()
 		parent.update_ordered_qty()
 		parent.update_ordered_and_reserved_qty()