Hi @jack1
Could you please try to use the acf/save_post hook instead? This page should give you more idea about it: https://www.advancedcustomfields.com/resources/acfsave_post/.
So, your code should be something like this:
add_action('acf/save_post' , 'my_acf_save_post', 20 );
function my_acf_save_post( $post_id ) {
// only do this for application post type
if( !get_post_type($post_id) == 'application' ) return;
// initialize the post array
$post = array(
'ID' => $post_id,
);
// Some logic goes here to determine what taxonomy term the post is to be filed in
$post += ['tax_input' => array(
'taxonomy1_to_use' => $id_of_taxonomy_term1,
'taxonomy2_to_use' => $id_of_taxonomy_term2
)];
// remove the hook to avoid the infinite loop issue
// https://codex.wordpress.org/Function_Reference/wp_update_post#Caution_-_Infinite_loop
add_action('acf/save_post' , 'my_acf_save_post', 20 );
// insert the post
wp_update_post( $post );
// add the hook back
add_action('acf/save_post' , 'my_acf_save_post', 20 );
};
I hope this helps 🙂
