Thanks again John! So with your help I put this together and now it works like I want.
add_filter( 'acf/pre_save_post' , function( $post_id ) {
// check if this is to be a new post
if ( $post_id != 'new' ) {
return $post_id;
}
if ( isset( $_POST['add-to-cart'] ) && isset( $_POST['product_id'] ) ) {
unset( $_POST );
}
// return the new ID
return $post_id;
}, 10, 1 );