diff --git a/app/code/Magento/Quote/Model/Quote/Item/AbstractItem.php b/app/code/Magento/Quote/Model/Quote/Item/AbstractItem.php
index 058411abe720b..7d0c1cd139adc 100644
--- a/app/code/Magento/Quote/Model/Quote/Item/AbstractItem.php
+++ b/app/code/Magento/Quote/Model/Quote/Item/AbstractItem.php
@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2011 Adobe
+ * All Rights Reserved.
  */
 namespace Magento\Quote\Model\Quote\Item;
 
@@ -18,6 +18,7 @@
  *  - custom_price - new price that can be declared by user and recalculated during calculation process
  *  - original_custom_price - original defined value of custom price without any conversion
  *
+ * phpcs:disable Magento2.Classes.AbstractApi
  * @api
  * @method float getDiscountAmount()
  * @method \Magento\Quote\Model\Quote\Item\AbstractItem setDiscountAmount(float $amount)
@@ -255,7 +256,7 @@ public function setMessage($messages)
     /**
      * Add message of quote item to array of messages
      *
-     * @param   string $message
+     * @param mixed $message
      * @return $this
      */
     public function addMessage($message)
@@ -678,9 +679,7 @@ public function getTotalDiscountAmount()
             foreach ($children as $child) {
                 $totalDiscountAmount += $child->getDiscountAmount();
             }
-        } else {
-            $totalDiscountAmount = $this->getDiscountAmount();
         }
-        return $totalDiscountAmount;
+        return $totalDiscountAmount + $this->getDiscountAmount();
     }
 }
diff --git a/app/code/Magento/Quote/Test/Unit/Model/Quote/Item/AbstractItemTest.php b/app/code/Magento/Quote/Test/Unit/Model/Quote/Item/AbstractItemTest.php
index a6a809f623066..fea82729d4950 100644
--- a/app/code/Magento/Quote/Test/Unit/Model/Quote/Item/AbstractItemTest.php
+++ b/app/code/Magento/Quote/Test/Unit/Model/Quote/Item/AbstractItemTest.php
@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2014 Adobe
+ * All Rights Reserved.
  */
 declare(strict_types=1);
 
@@ -50,7 +50,8 @@ public function testGetTotalDiscountAmount($expectedDiscountAmount, $children, $
         $this->assertEquals($expectedDiscountAmount, $totalDiscountAmount);
     }
 
-    protected function getMockForAbstractItem($childDiscountAmount) {
+    protected function getMockForAbstractItem($childDiscountAmount)
+    {
         $childItemMock = $this->getMockForAbstractClass(
             AbstractItem::class,
             [],
@@ -82,6 +83,7 @@ public static function dataProviderGetTotalDiscountAmount()
         $testCase->getMockForAbstractItem($childTwoDiscountAmount);
 
         $valueHasNoEffect = 0;
+        $parentDiscountAmount = 10;
 
         $data = [
             'no_children' => [
@@ -97,10 +99,10 @@ public static function dataProviderGetTotalDiscountAmount()
                 10,
             ],
             'one_kid' => [
-                $childOneDiscountAmount,
+                $childOneDiscountAmount + $parentDiscountAmount,
                 [$childOneItemMock],
                 true,
-                $valueHasNoEffect,
+                $parentDiscountAmount,
             ],
             'two_kids' => [
                 $childOneDiscountAmount + $childTwoDiscountAmount,
diff --git a/app/code/Magento/SalesRule/Model/Quote/Discount.php b/app/code/Magento/SalesRule/Model/Quote/Discount.php
index 1b790bf4bfc60..d2daad17f5eb9 100644
--- a/app/code/Magento/SalesRule/Model/Quote/Discount.php
+++ b/app/code/Magento/SalesRule/Model/Quote/Discount.php
@@ -188,10 +188,10 @@ public function collect(
         $items = $this->calculator->sortItemsByPriority($items, $address);
         $itemsToApplyRules = $items;
         $rules = $this->calculator->getRules($address);
-        $totalDiscount = [];
         $address->setBaseDiscountAmount(0);
         /** @var Rule $rule */
         foreach ($rules as $rule) {
+            $ruleTotalDiscount = 0;
             /** @var Item $item */
             foreach ($itemsToApplyRules as $key => $item) {
                 if ($item->getNoDiscount() || !$this->calculator->canApplyDiscount($item) || $item->getParentItem()) {
@@ -222,16 +222,13 @@ public function collect(
                 }
 
                 if ($item->getChildren() && $item->isChildrenCalculated()) {
-                    $childTotal = 0;
                     foreach ($item->getChildren() as $child) {
-                        $childTotal += $child->getBaseDiscountAmount();
+                        $ruleTotalDiscount += $child->getBaseDiscountAmount();
                     }
-                    $totalDiscount[$item->getId()] = $childTotal;
-                } else {
-                    $totalDiscount[$item->getId()] = $item->getBaseDiscountAmount();
                 }
+                $ruleTotalDiscount += $item->getBaseDiscountAmount();
             }
-            $address->setBaseDiscountAmount(array_sum(array_values($totalDiscount)));
+            $address->setBaseDiscountAmount($ruleTotalDiscount);
         }
         $this->calculator->initTotals($items, $address);
         foreach ($items as $item) {
diff --git a/app/code/Magento/SalesRule/Model/Rule/Action/Discount/CartFixed.php b/app/code/Magento/SalesRule/Model/Rule/Action/Discount/CartFixed.php
index 485b98c22565c..6cefea2557daa 100644
--- a/app/code/Magento/SalesRule/Model/Rule/Action/Discount/CartFixed.php
+++ b/app/code/Magento/SalesRule/Model/Rule/Action/Discount/CartFixed.php
@@ -1,7 +1,7 @@
 <?php
 /**
- * Copyright © Magento, Inc. All rights reserved.
- * See COPYING.txt for license details.
+ * Copyright 2014 Adobe
+ * All Rights Reserved.
  */
 namespace Magento\SalesRule\Model\Rule\Action\Discount;
 
@@ -141,6 +141,9 @@ public function calculate($rule, $item, $qty)
             $baseDiscountAmount = min($baseItemPrice * $qty, $baseDiscountAmount);
             if ($ruleItemsCount <= 1) {
                 $this->deltaPriceRound->reset($discountType);
+                if ($baseDiscountAmount > $availableDiscountAmount) {
+                    $baseDiscountAmount = $availableDiscountAmount;
+                }
             } else {
                 $this->validator->decrementRuleItemTotalsCount($rule->getId());
             }
@@ -191,6 +194,7 @@ public function calculate($rule, $item, $qty)
      * Set information about usage cart fixed rule by quote address
      *
      * @deprecated 101.2.0 should be removed as it is not longer used
+     * @see Nothing
      * @param int $ruleId
      * @param int $itemId
      * @return void
@@ -204,6 +208,7 @@ protected function setCartFixedRuleUsedForAddress($ruleId, $itemId)
      * Retrieve information about usage cart fixed rule by quote address
      *
      * @deprecated 101.2.0 should be removed as it is not longer used
+     * @see Nothing
      * @param int $ruleId
      * @return int|null
      */