• Squideyes

• January 19, 2020 at 6:08 am

Ah… I think you may have solved it.

I only have two fields (hero_image and thumbnail_image). These are set to appear on all pages and posts including custom post types.

I’ve just looked in my header.php file and look at what I found:

<?php
	// Get post ID
	$post_id = get_queried_object_id();
	// Hero image
	$hero = get_field('hero_image', $post_id);
	$hero_url = wp_get_attachment_url( get_field('hero_image', $post_id), 'hero');
?>

<?php if ( is_single() || is_archive() ): ?>
	<header id="masthead" class="site-header">
<?php else: ?>
	<header id="masthead" <?php if ($hero) { echo 'class="site-header has-background" style="background:url('.$hero_url.')"'; } else { echo 'class="site-header"'; } ?>>
<?php endif; ?>

I’ve renamed $post_id in header.php to $post_id_outside_loop. I’ve then used this variable via single.php as it’s also outside the loop. This has solved the issue.

For anyone that stumbles across this, see this post for more info.