Advanced Layout Builder – can't enable Layout meta box

We’re using the latest WordPress and Enfold versions, using the code from here to enable the “Layout” meta box for our CPT: https://kriesi.at/documentation/enfold/intro-to-layout-builder/#alb-for-any-post-type

Code used is:

function avf_metabox_layout_post_types_mod( array $supported_post_types ) {
 $supported_post_types[] = 'products';
 return $supported_post_types;
}
add_filter('avf_metabox_layout_post_types', 'avf_metabox_layout_post_types_mod', 10, 1);

I’ve modified the code appropriately for our “products” CPT and placed it in our child theme functions.php file. The ALB is enabled using the code from those instructions and works fine, but the Layout meta box does not show. We don’t have the Classic Editor or Gutenberg plugins installed, so its using the native WP version of Gutenberg.