The jQuery easing script is loaded with the theme to provide a nicer animation for the back to scroll button or other local scroll effects on the site. However, the script can be removed and the theme will use default animations instead.
add_action( 'wp_enqueue_scripts', function() {
wp_deregister_script( 'wpex-easing' );
wp_dequeue_script( 'wpex-easing' );
}, PHP_INT_MAX );