Attempts to remove all shutdown actions if file is being downloaded via WC.

functions.php

<?php // only copy this line if needed

/**
 * Attempts to remove all shutdown actions if file is being downloaded via WC.
 */
function remove_all_shutdown_actions_20200618() {
	remove_all_actions( 'shutdown' );
}
add_action( 'woocommerce_download_file_redirect', 'remove_all_shutdown_actions_20200618', 1 );
add_action( 'woocommerce_download_file_xsendfile', 'remove_all_shutdown_actions_20200618', 1 );
add_action( 'woocommerce_download_file_force', 'remove_all_shutdown_actions_20200618', 1 );