This makes sense, but the code the order give by @yousan will cause other problem, like a “headers already sent” error.
If you must do this then I would suggest adding an output buffer to prevent the error, and to be honest I’m not sure this won’t cause other problems.
<?php
ob_start();
get_header();
acf_form_head(); // <--- here!
echo ob_get_clean();
?>
