guy_b solution:
//Remove WPAUTOP from ACF TinyMCE Editor
function acf_wysiwyg_remove_wpautop() {
remove_filter('acf_the_content', 'wpautop' );
}
add_action('acf/init', 'acf_wysiwyg_remove_wpautop');<code></code>
worked for me
both on field and subfield
Thanks!