diff --git a/src/wp-includes/class-wp-theme-json-resolver.php b/src/wp-includes/class-wp-theme-json-resolver.php
index 2e6b7523b695c..d352cbdcbfdc8 100644
--- a/src/wp-includes/class-wp-theme-json-resolver.php
+++ b/src/wp-includes/class-wp-theme-json-resolver.php
@@ -559,7 +559,8 @@ public static function get_merged_data( $origin = 'custom' ) {
 			_deprecated_argument( __FUNCTION__, '5.9.0' );
 		}
 
-		$result = static::get_core_data();
+		$result = new WP_Theme_JSON();
+		$result->merge( static::get_core_data() );
 		if ( 'default' === $origin ) {
 			$result->set_spacing_sizes();
 			return $result;
diff --git a/tests/phpunit/tests/theme/wpThemeJsonResolver.php b/tests/phpunit/tests/theme/wpThemeJsonResolver.php
index 9b9185b224a39..b64953194367d 100644
--- a/tests/phpunit/tests/theme/wpThemeJsonResolver.php
+++ b/tests/phpunit/tests/theme/wpThemeJsonResolver.php
@@ -848,6 +848,49 @@ static function( $element ) {
 
 	}
 
+	/**
+	 * Tests that get_merged_data returns the data merged up to the proper origin
+	 * and that the core values have the proper data.
+	 *
+	 * @ticket 57824
+	 *
+	 * @covers WP_Theme_JSON_Resolver::get_merged_data
+	 *
+	 */
+	public function test_get_merged_data_returns_origin_proper() {
+		// Make sure the theme has a theme.json
+		// though it doesn't have any data for styles.spacing.padding.
+		switch_theme( 'block-theme' );
+
+		// Make sure the user defined some data for styles.spacing.padding.
+		wp_set_current_user( self::$administrator_id );
+		$user_cpt                               = WP_Theme_JSON_Resolver::get_user_data_from_wp_global_styles( wp_get_theme(), true );
+		$config                                 = json_decode( $user_cpt['post_content'], true );
+		$config['styles']['spacing']['padding'] = array(
+			'top'    => '23px',
+			'left'   => '23px',
+			'bottom' => '23px',
+			'right'  => '23px',
+		);
+		$user_cpt['post_content']               = wp_json_encode( $config );
+		wp_update_post( $user_cpt, true, false );
+
+		// Query data from the user origin and then for the theme origin.
+		$theme_json_user  = WP_Theme_JSON_Resolver::get_merged_data( 'custom' );
+		$padding_user     = $theme_json_user->get_raw_data()['styles']['spacing']['padding'];
+		$theme_json_theme = WP_Theme_JSON_Resolver::get_merged_data( 'theme' );
+		$padding_theme    = $theme_json_theme->get_raw_data()['styles']['spacing']['padding'];
+
+		$this->assertSame( '23px', $padding_user['top'] );
+		$this->assertSame( '23px', $padding_user['right'] );
+		$this->assertSame( '23px', $padding_user['bottom'] );
+		$this->assertSame( '23px', $padding_user['left'] );
+		$this->assertSame( '0px', $padding_theme['top'] );
+		$this->assertSame( '0px', $padding_theme['right'] );
+		$this->assertSame( '0px', $padding_theme['bottom'] );
+		$this->assertSame( '0px', $padding_theme['left'] );
+	}
+
 	/**
 	 * Data provider.
 	 *