get_fields in the save_post hook

Hello,

I nhave a acf that is filter to be filled after a specific category is selected.
I need to get this field data on wp save_post hook, I’d even try the wp_after_insert_post hook, booth withouth succes.

Searching answers I’d find a lot of references to the ‘acf/save_post’ hook.
I just try to get what data this hook have but with no success either.

The code to test the acf/save_post hook on my functions.php theme file:

function test_acf($post_id) {
   error_log( 'Saved post ID : ' . $post_id, false);
   error_log( var_export($_POST, true), false );

   //If you want to log what got saved to the database
   error_log( var_export(get_post($post_id), true), false );
}
add_action('acf/save_post', 'test_acf', 20);