vendor/fooman/pdfcustomiser-implementation-m2/src/Block/AbstractSalesDocument.php
add after $block->setTemplate($this->templateFileDecider->pick($this->getDesign(), 'shipping')); (line 375)
if(array_key_exists('channel_order_id', $this->getOrder()->getPayment()->getAdditionalInformation())) {
$m2epro_description = 'Ordine ';
$m2epro_description .= $this->getOrder()->getPayment()->getAdditionalInformation()['component_mode'];
$m2epro_description .= ': ';
$m2epro_description .= $this->getOrder()->getPayment()->getAdditionalInformation()['channel_order_id'];
$block->setShippingDescription($m2epro_description);
} else {
$block->setShippingDescription($this->getOrder()->getShippingDescription());
}