upnp servers

[angstrom]

Hi, I am absolutely loving this app but having difficulty accessing my NAS (Synology Diskstation). When I select UPNP/DLNA media server UAPP finds the BubbleUPNP servers on my phone and on my tablet but doesn't find the Diskstation Media Server.
I have also tried getting to it via Network, but none of the addresses I enter seem to work.  

Any ideas? thanks in advance!