Link-OS SDK for Xamarin does not work with iPod when connecting to ZD500 Printer by Wifi

Hi,

I am trying to use Link-OS SDK Xamarin to create connection to ZD 500 printer by Wifi. It works perfectly on Android. But when I test iOS project with a iPod (ios version 9.3), it is not working.

When the program run to line:

connection.Open();

it failed and gives nothing in exception. (open connection failed and nothing in response).

I also tried to download a Zebra Utility App and input the ip address and port number and it says ""