Exclude attendee's that have been cancelled from the attendee reports by default in EE3. Requires 3.1.37+

custom_functions.php

<?php //Please do not include the opening PHP tag

function espresso_exclude_cancelled_payment_status() {
	return ' AND a.payment_status != "Cancelled"';
}
add_filter('espresso_attendee_report_payment_status_where', 'espresso_exclude_cancelled_payment_status');

?>