Hi John, 
this is the limit for the sales order for the 8.5 version, 
but I want to ask about what you wrote "....Delivery Note for Items in a Sales Order with more than 199 Items" 
so did the customer managed to enter more that 199 to a sale order? and if yes, is this sale order was created under which version? is it 8.5 2020-01-07 version or from before?