diff --git a/addons/sale/models/sale_order.py b/addons/sale/models/sale_order.py
index c133b9f8cbf..d71d4eeb770 100644
--- a/addons/sale/models/sale_order.py
+++ b/addons/sale/models/sale_order.py
@@ -742,6 +742,12 @@ Reason(s) of this behavior could be:
         if not grouped:
             new_invoice_vals_list = []
             invoice_grouping_keys = self._get_invoice_grouping_keys()
+            invoice_vals_list = sorted(
+                invoice_vals_list,
+                key=lambda x: [
+                    x.get(grouping_key) for grouping_key in invoice_grouping_keys
+                ]
+            )
             for grouping_keys, invoices in groupby(invoice_vals_list, key=lambda x: [x.get(grouping_key) for grouping_key in invoice_grouping_keys]):
                 origins = set()
                 payment_refs = set()