Fix issue 10347

Author: Pieter Cappelle

app/code/Magento/Tax/Model/Plugin/OrderSave.php

@@ -97,8 +97,12 @@ protected function saveOrderTax(\Magento\Sales\Api\Data\OrderInterface $order)
                         } else {
                             $percentSum = 0;
                             foreach ($taxRates as $rate) {
-                                $realAmount = $rates['amount'] * $rate['percent'] / $rates['percent'];
-                                $realBaseAmount = $rates['base_amount'] * $rate['percent'] / $rates['percent'];
+                                $percentSum += $rate['percent'];
+                            }
+
+                            foreach ($taxRates as $rate) {
+                                $realAmount = $rates['amount'] * $rate['percent'] / $percentSum;
+                                $realBaseAmount = $rates['base_amount'] * $rate['percent'] / $percentSum;
                                 $ratesIdQuoteItemId[$rates['id']][] = [
                                     'id' => $taxesArray['item_id'],
                                     'percent' => $rate['percent'],
@@ -110,7 +114,6 @@ protected function saveOrderTax(\Magento\Sales\Api\Data\OrderInterface $order)
                                     'real_amount' => $realAmount,
                                     'real_base_amount' => $realBaseAmount,
                                 ];
-                                $percentSum += $rate['percent'];
                             }
                         }
                     }