Text areas are not designed for shortcodes, but you could try something like:
function text_area_shortcode($value, $post_id, $field) {
if (is_admin()) {
// don't do this in the admin
// could have unintended side effects
return;
}
do_shortcode($value);
return $value;
}
add_filter('acf/load_value/type=textarea', 'text_area_shortcode', 10, 3);
You could limit this to only a specific field by changing the hook to ‘acf/load_value/name={$field_name}’ or you could check $field inside the function for specific field names, or even add multiple add_filter() calls for different fields. Depends on how many text areas you want to filter and use shortcodes in.
acf/load_value hook documentation
