diff -r 34716fd837a4 -r be944660c56a wp/wp-includes/customize/class-wp-customize-nav-menu-section.php
--- a/wp/wp-includes/customize/class-wp-customize-nav-menu-section.php	Tue Dec 15 15:52:01 2020 +0100
+++ b/wp/wp-includes/customize/class-wp-customize-nav-menu-section.php	Wed Sep 21 18:19:35 2022 +0200
@@ -34,7 +34,7 @@
 	 */
 	public function json() {
 		$exported            = parent::json();
-		$exported['menu_id'] = intval( preg_replace( '/^nav_menu\[(-?\d+)\]/', '$1', $this->id ) );
+		$exported['menu_id'] = (int) preg_replace( '/^nav_menu\[(-?\d+)\]/', '$1', $this->id );
 
 		return $exported;
 	}