Still not sure why the values aren’t loading but I solved the issue.
I was also, in conjunction with the code snippet above using the following ‘prepare_field’ hooks:
function my_acf_prepare( $field ) {
/* this was added to fix above */
$field['value'] = htmlspecialchars($_GET["xxx"]);
/* this was always here */
$field['readonly'] = true;
return $field;
}
add_filter('acf/prepare_field/name=zzz', 'my_acf_prepare');
I just added a ‘value’ $field object into the prepare field code above that just assigns a value to the field during the prepare_field action instead of using ‘load_value’ from above in cojunction with the ‘prepare_field’ hook.
Hope this helps someone else.
