If you're submitting a form using GForms and populating ACF you'll need ot run this script on save to push the fields into ACF correctly

und2_form_resubmit_fields.php

/**
 * Save Form Items to ACF Properly
 *
 *
 */
function und2_form_resubmit_fields($entry, $form){
	$args = array(
	    'post_type' =>'CUSTOM_POST_TYPE',
	    'posts_per_page' => 1
	);
	$recent_posts = wp_get_recent_posts($args);

	foreach( $recent_posts as $recent ){
		$id = $recent['ID'];
		$field_group_id = 7; // This needs to be the ID of your custom fields

		$fields = acf_get_fields( $field_group_id );

		foreach( $fields as $field ) {
			$name = $field['name'];
			update_field($name, get_field( $name, $id) , $id);
		}
		
	}

} 
// Replace XX with your Gravity Forms ID
add_action( 'gform_after_submission_XX', 'und2_form_resubmit_fields', 10, 2 );