n-Serve will not "Discover" Server - NDX

I need some help to get n-Serve working ……… I have a feeling I ’m missing something stupidly obvious, but bear with me as I’m a newbie at this streaming & apps m’larky. 

n-Stream works fine, no probs, it all worked straight out of the box. 

n-Serve will not “discover” the server – tried many times, junked & reloaded the app, played with DHCP on/off & a bunch of other stuff I can’t remember.

I have come to the conclusion it’s a problem with the app as the manual IP address function will not open up to let me write in the IP.  I looked around the iPad settings & can’t see anything that is associated with this,  also this function does open on the n-Stream app so it kinda confirms its in the n-Serve app. 

Help will be much appreciated.