Invalid printer name

I am trying to print to a zebra ZP 450 using raw type, but I am getting an invalid printer name error returned when getting to the openPrinter() within the SendBytesToPrinter function. I can find Microsoft XPS writer printer just fine. The printer has been printing great from other software and I've triple checked the printer name. Any ideas what could be going wrong with the discovery? My code is based on this - SendToPrinter/RawPrinterHelper.cs at master · andyyou/SendToPrinter · GitHub