Code to Disable Lazy Loading in WordPress

/* Disable Lazy Load WordPress Sitewide */
add_filter( 'wp_lazy_loading_enabled', '__return_false' );

Since WordPress 5.5, Lazy Loading works by default. WordPress automatically adds loading=“lazy” syntax to all the images on the site including the Featured Image. Add this to your child theme’s functions.php to completely disable the default WordPress Lazy Loading function.