diff -Nuar a/vendor/magento/module-reward/Model/Action/OrderExtra.php b/vendor/magento/module-reward/Model/Action/OrderExtra.php
index d43c48be87b..0897fce8f0b 100644
--- a/vendor/magento/module-reward/Model/Action/OrderExtra.php
+++ b/vendor/magento/module-reward/Model/Action/OrderExtra.php
@@ -130,7 +130,10 @@ class OrderExtra extends \Magento\Reward\Model\Action\AbstractAction
             } else {
                 $monetaryAmount = $this->getEntity()->getTotalPaid() -
                     $this->getEntity()->getShippingAmount() -
-                    $this->getEntity()->getTaxAmount();
+                    (
+                        $this->getEntity()->getTaxAmount() -
+                        $this->getEntity()->getTaxCanceled()
+                    );
             }
         }
         $pointsDelta = $this->getReward()->getRateToPoints()->calculateToPoints((double)$monetaryAmount);
@@ -139,7 +142,8 @@ class OrderExtra extends \Magento\Reward\Model\Action\AbstractAction
 
     /**
      * Check whether rewards can be added for action
-     * Checking for the history records is intentionaly omitted
+     *
+     * Checking for the history records is intentionally omitted
      *
      * @return bool
      */
@@ -149,6 +153,8 @@ class OrderExtra extends \Magento\Reward\Model\Action\AbstractAction
     }
 
     /**
+     * Get tax config
+     *
      * @return \Magento\Tax\Model\Config|mixed|null
      * @deprecated 101.0.2
      */
diff -Nuar a/vendor/magento/module-reward/Observer/OrderCompleted.php b/vendor/magento/module-reward/Observer/OrderCompleted.php
index 7daf4e189d5..4d1a0f7b9ce 100644
--- a/vendor/magento/module-reward/Observer/OrderCompleted.php
+++ b/vendor/magento/module-reward/Observer/OrderCompleted.php
@@ -6,31 +6,37 @@
  */
 namespace Magento\Reward\Observer;
 
+use Exception;
+use Magento\Framework\Event\Observer;
 use Magento\Framework\Event\ObserverInterface;
+use Magento\Reward\Helper\Data;
+use Magento\Reward\Model\Reward;
+use Magento\Reward\Model\RewardFactory;
+use Magento\Sales\Model\Order;
 
 class OrderCompleted implements ObserverInterface
 {
     /**
      * Reward factory
      *
-     * @var \Magento\Reward\Model\RewardFactory
+     * @var RewardFactory
      */
     protected $_rewardFactory;
 
     /**
      * Reward helper
      *
-     * @var \Magento\Reward\Helper\Data
+     * @var Data
      */
     protected $_rewardData;
 
     /**
-     * @param \Magento\Reward\Helper\Data $rewardData
-     * @param \Magento\Reward\Model\RewardFactory $rewardFactory
+     * @param Data $rewardData
+     * @param RewardFactory $rewardFactory
      */
     public function __construct(
-        \Magento\Reward\Helper\Data $rewardData,
-        \Magento\Reward\Model\RewardFactory $rewardFactory
+        Data $rewardData,
+        RewardFactory $rewardFactory
     ) {
         $this->_rewardData = $rewardData;
         $this->_rewardFactory = $rewardFactory;
@@ -38,15 +44,21 @@ class OrderCompleted implements ObserverInterface
 
     /**
      * Check if order is paid exactly now
+     *
      * If order was paid before Rewards were enabled, reward points should not be added
      *
-     * @param \Magento\Sales\Model\Order $order
+     * @param Order $order
      * @return bool
      */
     protected function _isOrderPaidNow($order)
     {
-        $isOrderPaid = (double)$order->getBaseTotalPaid() > 0 &&
-            $order->getBaseGrandTotal() - $order->getBaseSubtotalCanceled() - $order->getBaseTotalPaid() < 0.0001;
+        $baseGrandTotal = (float) $order->getBaseGrandTotal();
+        $baseSubtotalCanceled = (float) $order->getBaseSubtotalCanceled();
+        $baseTaxCanceled = (float) $order->getBaseTaxCanceled();
+        $baseTotalPaid = (float) $order->getBaseTotalPaid();
+        $totalAmountPaid = $baseGrandTotal - ($baseSubtotalCanceled + $baseTaxCanceled + $baseTotalPaid);
+        $isOrderPaid = (double) $order->getBaseTotalPaid() > 0 &&
+            $totalAmountPaid < 0.0001;
 
         if (!$order->getOrigData('base_grand_total')) {
             //New order with "Sale" payment action
@@ -58,6 +70,8 @@ class OrderCompleted implements ObserverInterface
         ) - $order->getOrigData(
             'base_subtotal_canceled'
         ) - $order->getOrigData(
+            'base_tax_canceled'
+        ) - $order->getOrigData(
             'base_total_paid'
         ) >= 0.0001;
     }
@@ -65,19 +79,20 @@ class OrderCompleted implements ObserverInterface
     /**
      * Update points balance after order becomes completed
      *
-     * @param \Magento\Framework\Event\Observer $observer
+     * @param Observer $observer
      * @return $this
+     * @throws Exception
      */
-    public function execute(\Magento\Framework\Event\Observer $observer)
+    public function execute(Observer $observer)
     {
-        /* @var $order \Magento\Sales\Model\Order */
+        /* @var $order Order */
         $order = $observer->getEvent()->getOrder();
         if ($order->getCustomerIsGuest() || !$this->_rewardData->isEnabledOnFront($order->getStore()->getWebsiteId())) {
             return $this;
         }
 
         if ($order->getCustomerId() && $this->_isOrderPaidNow($order)) {
-            /* @var $reward \Magento\Reward\Model\Reward */
+            /* @var $reward Reward */
             $reward = $this->_rewardFactory->create()->setActionEntity(
                 $order
             )->setCustomerId(
@@ -85,7 +100,7 @@ class OrderCompleted implements ObserverInterface
             )->setWebsiteId(
                 $order->getStore()->getWebsiteId()
             )->setAction(
-                \Magento\Reward\Model\Reward::REWARD_ACTION_ORDER_EXTRA
+                Reward::REWARD_ACTION_ORDER_EXTRA
             )->updateRewardPoints();
             if ($reward->getRewardPointsUpdated() && $reward->getPointsDelta()) {
                 $order->addStatusHistoryComment(