Multifunction printers can be challenging where print servers are concerned, especially when the print servers do not provide a "back channel" to allow bi-directional communications - which the DNS-323 does not do.
How I would deal with this is to take a known working installation of the printer with a direct USB connection and edit it to point to the shared printer - go to ports and create a new local port named \\<ip-address-of-DNS-323>\lp - also check the printer properties in the driver and disable bi-directional printer support and see what happens.