Moving the get_header();
above acf_form_head();
worked, the images are now being uploaded and the ‘add row’ is now working, but I’m getting an error after submission:
Warning: Cannot modify header information – headers already sent by (output started at C:…wp-includes\class.wp-styles.php:214) in …\wp-includes\pluggable.php on line 1340
not sure what’s going on