Load acf_form_head for use in Popup

Hi,
I am using a ACF form inside a popup (Elementor).
I have included this in my functions.php to enqueue all ACF related scripts and styles :

//adding AFC form head
function add_acf_form_head(){
        acf_form_head();
}
add_action( 'wp_head', 'add_acf_form_head', 7 );

The form submits and saves and he styles load, however only sometimes do they load correctly – i.e the conditional fields showing, the active buttons showing as active etc. If I increase the priority of the add_action I get an error :

Warning: Cannot modify header information - headers already sent by....

I have also tried putting acf_form_head() directly in the header.php file but with the sae results – any suggestions?
Thanks