Hi, I've created a custom field into the sales order line that I manually populate. I would like to report this value into each invoice line when I create an invoice from the sales order(s). So I created a new related field inside the invoice that points to the fiend if the sales order line with this string purchase_line_id.sale_order_id.order_line.x_studio_po_reference but for some reason this does not work and the related field inside the invoice is always empty. How do I fix this? which parameters I have to check? thanks