Error adding as thumbnail the first image from the gallery

This code below (I used the code that was shared on github https://github.com/Crocoblock/suggestions/issues/3985) was working perfectly in my form, but I updated from the latest version (2.1.6) and now is no longer adding the image as a thumbnail of the post. Does it have any solution?

add_action( 'save_post', function ( $post_id ) {

	if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
		return;
	}

	$gallery_key = 'property_photos';

	$gallery = get_post_meta( $post_id, $gallery_key, true );

	if ( empty( $gallery ) ) {
		return;
	}

	$gallery = explode( ',', $gallery );

	$image_id = $gallery[0];
	set_post_thumbnail( $post_id, $image_id );

}, 99 );

• This topic was modified 2 years, 5 months ago by thiagotask.