If order notes are added via AutomateWoo, they do not have a user associated with them. This is an example of how to make it so a user is added to a note added by AW.

functions.php

<?php // do not copy this line

/**
 * Adds hook to the AutomateWoo order paid action to add a filter. 
 */
add_action( 'automatewoo/order/paid_async', 'add_automatewoo_note_filter_20200702' );
function add_automatewoo_note_filter_20200702() {
	add_filter( 'woocommerce_new_order_note_data', 'add_author_to_automatewoo_note_20200702' ); 
}

/**
 * Filter will take a user id (50) and then add the order note under that user.
 */
function add_author_to_automatewoo_note_20200702( $note_data ) {
	$user                              = get_user_by( 'id', 50 );
	$note_data['comment_author']       = $user->display_name;
	$note_data['comment_author_email'] = $user->user_email;
	return $note_data;
}