diff --git a/composer.json b/composer.json
index a6583c20..07e34300 100644
--- a/composer.json
+++ b/composer.json
@@ -75,7 +75,7 @@
         "stan": "phpstan analyze --ansi --memory-limit=4G",
         "strauss": [
             "test -f ./bin/strauss.phar || curl -o bin/strauss.phar -L -C - https://github.com/BrianHenryIE/strauss/releases/download/0.14.0/strauss.phar",
-            "@php bin/strauss.phar",
+            "env -u COMPOSER_AUTH COMPOSER_HOME=$(mktemp -d) php bin/strauss.phar",
             "composer dump-autoload --optimize"
         ],
         "cghooks": [
diff --git a/includes/class-woocommerce.php b/includes/class-woocommerce.php
index 21ee1392..359e333e 100644
--- a/includes/class-woocommerce.php
+++ b/includes/class-woocommerce.php
@@ -124,14 +124,36 @@ class WooCommerce {
 	 * @return boolean
 	 */
 	public static function should_load_session_handler() {
+		// Any request carrying either the Store-API Cart-Token header or the
+		// legacy `woocommerce-session` (filterable) header is a headless
+		// caller driving session state through the token, regardless of
+		// which WP endpoint it lands on (admin-ajax, REST, the front-end,
+		// etc.). We need QL_Session_Handler here too so the session is
+		// bootstrapped from the token instead of the (absent) WC session
+		// cookie.
+		$legacy_header_key  = 'HTTP_' . strtoupper(
+			preg_replace(
+				'#[^A-z0-9]#',
+				'_',
+				apply_filters( 'graphql_woocommerce_cart_session_http_header', 'woocommerce-session' )
+			)
+		);
+		$has_session_header = ! empty( $_SERVER['HTTP_CART_TOKEN'] ) // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized, WordPress.Security.ValidatedSanitizedInput.MissingUnslash
+			|| ! empty( $_SERVER[ $legacy_header_key ] ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized, WordPress.Security.ValidatedSanitizedInput.MissingUnslash
+
 		switch ( true ) {
 			case \WPGraphQL\Router::is_graphql_http_request():
 			//phpcs:disable
 			case 'on' === woographql_setting( 'enable_ql_session_handler_on_ajax', 'off' )
-				&& ( ! empty( $_GET['wc-ajax'] ) || defined( 'WC_DOING_AJAX' ) ):
+				&& (
+					! empty( $_GET['wc-ajax'] )
+					|| defined( 'WC_DOING_AJAX' )
+					|| wp_doing_ajax()
+					|| $has_session_header
+				):
 			//phpcs:enable
 			case 'on' === woographql_setting( 'enable_ql_session_handler_on_rest', 'off' )
-				&& ( defined( 'REST_REQUEST' ) && REST_REQUEST ):
+				&& ( ( defined( 'REST_REQUEST' ) && REST_REQUEST ) || $has_session_header ):
 				return true;
 			default:
 				return false;
diff --git a/includes/data/mutation/class-checkout-mutation.php b/includes/data/mutation/class-checkout-mutation.php
index 8498543c..16ce19a9 100644
--- a/includes/data/mutation/class-checkout-mutation.php
+++ b/includes/data/mutation/class-checkout-mutation.php
@@ -164,6 +164,7 @@ class Checkout_Mutation {
 				'postcode'   => 'postcode',
 				'state'      => 'state',
 				'country'    => 'country',
+				'phone'      => 'phone',
 			],
 			'account'  => [
 				'username' => 'username',
diff --git a/tests/wpunit/CheckoutMutationTest.php b/tests/wpunit/CheckoutMutationTest.php
index c22eb2d9..aaa1a5e6 100644
--- a/tests/wpunit/CheckoutMutationTest.php
+++ b/tests/wpunit/CheckoutMutationTest.php
@@ -133,6 +133,7 @@ class CheckoutMutationTest extends \Tests\WPGraphQL\WooCommerce\TestCase\WooGrap
 							state
 							postcode
 							country
+							phone
 						}
 						paymentMethod
 						paymentMethodTitle
@@ -293,6 +294,7 @@ class CheckoutMutationTest extends \Tests\WPGraphQL\WooCommerce\TestCase\WooGrap
 					'state'     => 'NY',
 					'postcode'  => '12345',
 					'country'   => 'US',
+					'phone'     => '555-555-6789',
 				],
 				'metaData'       => [
 					[
@@ -446,6 +448,8 @@ class CheckoutMutationTest extends \Tests\WPGraphQL\WooCommerce\TestCase\WooGrap
 				'checkout.customer.id',
 				$this->toRelayId( 'user', $this->customer )
 			),
+			$this->expectedField( 'checkout.order.billing.phone', '555-555-1234' ),
+			$this->expectedField( 'checkout.order.shipping.phone', '555-555-6789' ),
 			$this->expectedField( 'checkout.result', 'success' ),
 			$this->expectedField( 'checkout.redirect', static::NOT_NULL ),
 		];
@@ -463,6 +467,44 @@ class CheckoutMutationTest extends \Tests\WPGraphQL\WooCommerce\TestCase\WooGrap
 		$this->assertQuerySuccessful( $response, $expected );
 	}
 
+	public function testCheckoutMutationPersistsShippingPhone() {
+		$this->loginAsCustomer();
+
+		$product_id = $this->factory->product->createSimple();
+		WC()->cart->add_to_cart( $product_id, 1 );
+
+		$input     = [
+			'shipping' => [
+				'firstName' => 'May',
+				'lastName'  => 'Parker',
+				'address1'  => '20 Ingram St',
+				'city'      => 'New York City',
+				'state'     => 'NY',
+				'postcode'  => '12345',
+				'country'   => 'US',
+				'phone'     => '555-555-6789',
+			],
+		];
+		$variables = [ 'input' => $this->getCheckoutInput( $input ) ];
+		$query     = $this->getCheckoutMutation();
+
+		$response = $this->graphql( compact( 'query', 'variables' ) );
+
+		// The shipping phone is returned on the order and is distinct from the billing phone.
+		$this->assertQuerySuccessful(
+			$response,
+			[
+				$this->expectedField( 'checkout.order.billing.phone', '555-555-1234' ),
+				$this->expectedField( 'checkout.order.shipping.phone', '555-555-6789' ),
+			]
+		);
+
+		// And it is saved on the underlying WC_Order object.
+		$order_id = $response['data']['checkout']['order']['databaseId'];
+		$order    = \wc_get_order( $order_id );
+		$this->assertEquals( '555-555-6789', $order->get_shipping_phone() );
+	}
+
 	public function testCheckoutMutationWithNewAccount() {
 		$variable    = $this->factory->product_variation->createSome();
 		$product_ids = [