diff --git a/vendor/magento/module-multishipping/Model/Cart/CartTotalRepositoryPlugin.php b/vendor/magento/module-multishipping/Model/Cart/CartTotalRepositoryPlugin.php
index bb225a5c462..8d7c9361e55 100644
--- a/vendor/magento/module-multishipping/Model/Cart/CartTotalRepositoryPlugin.php
+++ b/vendor/magento/module-multishipping/Model/Cart/CartTotalRepositoryPlugin.php
@@ -49,7 +49,7 @@ class CartTotalRepositoryPlugin
         $cartId
     ) : Totals {
         $quote = $this->quoteRepository->getActive($cartId);
-        if ($quote->getIsMultiShipping()) {
+        if ($quote->isMultipleShippingAddresses()) {
             $shippingMethod = $quote->getShippingAddress()->getShippingMethod();
             if (isset($shippingMethod) && !empty($shippingMethod)) {
                 $shippingRate = $quote->getShippingAddress()->getShippingRateByCode($shippingMethod);
diff --git a/vendor/magento/module-multishipping/Model/Cart/Controller/CartPlugin.php b/vendor/magento/module-multishipping/Model/Cart/Controller/CartPlugin.php
index b450232395b..050be87dd07 100644
--- a/vendor/magento/module-multishipping/Model/Cart/Controller/CartPlugin.php
+++ b/vendor/magento/module-multishipping/Model/Cart/Controller/CartPlugin.php
@@ -12,7 +12,7 @@ use Magento\Checkout\Model\Session;
 use Magento\Customer\Api\AddressRepositoryInterface;
 use Magento\Framework\App\RequestInterface;
 use Magento\Framework\Exception\LocalizedException;
-use Magento\Multishipping\Model\Checkout\Type\Multishipping\State;
+use Magento\Multishipping\Model\DisableMultishipping;
 use Magento\Quote\Api\CartRepositoryInterface;
 use Magento\Quote\Model\Quote;

@@ -37,18 +37,26 @@ class CartPlugin
     private $addressRepository;

     /**
+     * @var DisableMultishipping
+     */
+    private $disableMultishipping;
+
+    /**
      * @param CartRepositoryInterface $cartRepository
      * @param Session $checkoutSession
      * @param AddressRepositoryInterface $addressRepository
+     * @param DisableMultishipping $disableMultishipping
      */
     public function __construct(
         CartRepositoryInterface $cartRepository,
         Session $checkoutSession,
-        AddressRepositoryInterface $addressRepository
+        AddressRepositoryInterface $addressRepository,
+        DisableMultishipping $disableMultishipping
     ) {
         $this->cartRepository = $cartRepository;
         $this->checkoutSession = $checkoutSession;
         $this->addressRepository = $addressRepository;
+        $this->disableMultishipping = $disableMultishipping;
     }

     /**
@@ -64,7 +72,8 @@ class CartPlugin
     {
         /** @var Quote $quote */
         $quote = $this->checkoutSession->getQuote();
-        if ($quote->isMultipleShippingAddresses() && $this->isCheckoutComplete()) {
+        if ($quote->isMultipleShippingAddresses() || $this->isDisableMultishippingRequired($request, $quote)) {
+            $this->disableMultishipping->execute($quote);
             foreach ($quote->getAllShippingAddresses() as $address) {
                 $quote->removeAddress($address->getId());
             }
@@ -76,16 +85,45 @@ class CartPlugin
                 $shippingAddress->importCustomerAddressData($defaultCustomerAddress);
             }
             $this->cartRepository->save($quote);
+        } elseif ($this->disableMultishipping->execute($quote) &&
+            ($this->isVirtualItemInQuote($quote) || $quote->isMultipleShippingAddresses())
+        ) {
+            $quote->setTotalsCollectedFlag(false);
+            $this->cartRepository->save($quote);
+        }
+    }
+
+    /**
+     * Checks whether quote has virtual items
+     *
+     * @param Quote $quote
+     * @return bool
+     */
+    private function isVirtualItemInQuote(Quote $quote): bool
+    {
+        $items = $quote->getItems();
+        if (!empty($items)) {
+            foreach ($items as $item) {
+                if ($item->getIsVirtual()) {
+                    return true;
+                }
+            }
         }
+
+        return false;
     }

     /**
-     * Checks whether the checkout flow is complete
+     * Check if we have to disable multishipping mode depends on the request action name
      *
+     * We should not disable multishipping mode if we are adding a new product item to the existing quote
+     *
+     * @param RequestInterface $request
+     * @param Quote $quote
      * @return bool
      */
-    private function isCheckoutComplete() : bool
+    private function isDisableMultishippingRequired(RequestInterface $request, Quote $quote): bool
     {
-        return (bool) ($this->checkoutSession->getStepData(State::STEP_SHIPPING)['is_complete'] ?? true);
+        return $request->getActionName() !== "add" && $quote->getIsMultiShipping();
     }
 }
diff --git a/vendor/magento/module-multishipping/Model/DisableMultishipping.php b/vendor/magento/module-multishipping/Model/DisableMultishipping.php
new file mode 100644
index 00000000000..a871cee7155
--- /dev/null
+++ b/vendor/magento/module-multishipping/Model/DisableMultishipping.php
@@ -0,0 +1,38 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Multishipping\Model;
+
+use Magento\Quote\Api\Data\CartInterface;
+
+/**
+ * Turn Off Multishipping mode if enabled.
+ */
+class DisableMultishipping
+{
+    /**
+     * Disable Multishipping mode for provided Quote and return TRUE if it was changed.
+     *
+     * @param CartInterface $quote
+     * @return bool
+     */
+    public function execute(CartInterface $quote): bool
+    {
+        $modeChanged = false;
+        if ($quote->getIsMultiShipping()) {
+            $quote->setIsMultiShipping(0);
+            $extensionAttributes = $quote->getExtensionAttributes();
+            if ($extensionAttributes && $extensionAttributes->getShippingAssignments()) {
+                $extensionAttributes->setShippingAssignments([]);
+            }
+
+            $modeChanged = true;
+        }
+
+        return $modeChanged;
+    }
+}
diff --git a/vendor/magento/module-multishipping/Observer/DisableMultishippingObserver.php b/vendor/magento/module-multishipping/Observer/DisableMultishippingObserver.php
new file mode 100644
index 00000000000..a72bce87965
--- /dev/null
+++ b/vendor/magento/module-multishipping/Observer/DisableMultishippingObserver.php
@@ -0,0 +1,46 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types=1);
+
+namespace Magento\Multishipping\Observer;
+
+use Magento\Framework\Event\ObserverInterface;
+use Magento\Framework\Event\Observer as EventObserver;
+use Magento\Multishipping\Model\DisableMultishipping;
+use Magento\Quote\Api\Data\CartInterface;
+
+/**
+ * Observer for disabling Multishipping mode.
+ */
+class DisableMultishippingObserver implements ObserverInterface
+{
+    /**
+     * @var DisableMultishipping
+     */
+    private $disableMultishipping;
+
+    /**
+     * @param DisableMultishipping $disableMultishipping
+     */
+    public function __construct(
+        DisableMultishipping $disableMultishipping
+    ) {
+        $this->disableMultishipping = $disableMultishipping;
+    }
+
+    /**
+     * Disable Multishipping mode before saving Quote.
+     *
+     * @param EventObserver $observer
+     * @return void
+     */
+    public function execute(EventObserver $observer): void
+    {
+        /** @var CartInterface $quote */
+        $quote = $observer->getEvent()->getCart()->getQuote();
+        $this->disableMultishipping->execute($quote);
+    }
+}
diff --git a/vendor/magento/module-multishipping/Plugin/DisableMultishippingMode.php b/vendor/magento/module-multishipping/Plugin/DisableMultishippingMode.php
index fff2346d762..f4e6928173f 100644
--- a/vendor/magento/module-multishipping/Plugin/DisableMultishippingMode.php
+++ b/vendor/magento/module-multishipping/Plugin/DisableMultishippingMode.php
@@ -9,6 +9,7 @@ namespace Magento\Multishipping\Plugin;

 use Magento\Checkout\Model\Cart;
 use Magento\Framework\App\Action\Action;
+use Magento\Multishipping\Model\DisableMultishipping;

 /**
  * Turns Off Multishipping mode for Quote.
@@ -21,12 +22,20 @@ class DisableMultishippingMode
     private $cart;

     /**
+     * @var DisableMultishipping
+     */
+    private $disableMultishipping;
+
+    /**
      * @param Cart $cart
+     * @param DisableMultishipping $disableMultishipping
      */
     public function __construct(
-        Cart $cart
+        Cart $cart,
+        DisableMultishipping $disableMultishipping
     ) {
         $this->cart = $cart;
+        $this->disableMultishipping = $disableMultishipping;
     }

     /**
@@ -36,16 +45,16 @@ class DisableMultishippingMode
      * @return void
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
-    public function beforeExecute(Action $subject)
+    public function beforeExecute(Action $subject): void
     {
         $quote = $this->cart->getQuote();
-        if ($quote->getIsMultiShipping()) {
-            $quote->setIsMultiShipping(0);
-            $extensionAttributes = $quote->getExtensionAttributes();
-            if ($extensionAttributes && $extensionAttributes->getShippingAssignments()) {
-                $extensionAttributes->setShippingAssignments([]);
-            }
+        $modChanged = $this->disableMultishipping->execute($quote);
+        if ($modChanged) {
+            $totalsCollectedBefore = $quote->getTotalsCollectedFlag();
             $this->cart->saveQuote();
+            if (!$totalsCollectedBefore) {
+                $quote->setTotalsCollectedFlag(false);
+            }
         }
     }
 }
diff --git a/vendor/magento/module-multishipping/etc/frontend/events.xml b/vendor/magento/module-multishipping/etc/frontend/events.xml
new file mode 100644
index 00000000000..219e358528c
--- /dev/null
+++ b/vendor/magento/module-multishipping/etc/frontend/events.xml
@@ -0,0 +1,12 @@
+<?xml version="1.0"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+-->
+<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:Event/etc/events.xsd">
+    <event name="checkout_cart_save_before">
+        <observer name="magento_multishipping_disabler" instance="Magento\Multishipping\Observer\DisableMultishippingObserver"/>
+    </event>
+</config>
diff --git a/vendor/magento/module-tax/Model/Sales/Total/Quote/CommonTaxCollector.php b/vendor/magento/module-tax/Model/Sales/Total/Quote/CommonTaxCollector.php
index c7cc4ded1bf..61530142822 100644
--- a/vendor/magento/module-tax/Model/Sales/Total/Quote/CommonTaxCollector.php
+++ b/vendor/magento/module-tax/Model/Sales/Total/Quote/CommonTaxCollector.php
@@ -565,21 +565,24 @@ class CommonTaxCollector extends AbstractTotal
             /** @var TaxDetailsItemInterface $baseTaxDetail */
             $baseTaxDetail = $itemTaxDetail[self::KEY_BASE_ITEM];
             $quoteItem = $keyedAddressItems[$code];
-            $this->updateItemTaxInfo($quoteItem, $taxDetail, $baseTaxDetail, $store);

-            //Update aggregated values
-            if ($quoteItem->getHasChildren() && $quoteItem->isChildrenCalculated()) {
-                //avoid double counting
-                continue;
+            if (!$quoteItem->isDeleted()) {
+                $this->updateItemTaxInfo($quoteItem, $taxDetail, $baseTaxDetail, $store);
+
+                //Update aggregated values
+                if ($quoteItem->getHasChildren() && $quoteItem->isChildrenCalculated()) {
+                    //avoid double counting
+                    continue;
+                }
+                $subtotal += $taxDetail->getRowTotal();
+                $baseSubtotal += $baseTaxDetail->getRowTotal();
+                $discountTaxCompensation += $taxDetail->getDiscountTaxCompensationAmount();
+                $baseDiscountTaxCompensation += $baseTaxDetail->getDiscountTaxCompensationAmount();
+                $tax += $taxDetail->getRowTax();
+                $baseTax += $baseTaxDetail->getRowTax();
+                $subtotalInclTax += $taxDetail->getRowTotalInclTax();
+                $baseSubtotalInclTax += $baseTaxDetail->getRowTotalInclTax();
             }
-            $subtotal += $taxDetail->getRowTotal();
-            $baseSubtotal += $baseTaxDetail->getRowTotal();
-            $discountTaxCompensation += $taxDetail->getDiscountTaxCompensationAmount();
-            $baseDiscountTaxCompensation += $baseTaxDetail->getDiscountTaxCompensationAmount();
-            $tax += $taxDetail->getRowTax();
-            $baseTax += $baseTaxDetail->getRowTax();
-            $subtotalInclTax += $taxDetail->getRowTotalInclTax();
-            $baseSubtotalInclTax += $baseTaxDetail->getRowTotalInclTax();
         }

         //Set aggregated values