My iPhone has never been detected by unreal. I have tried in shared connection with my iPhone through cable and wifi, and via private adsl wifi connection.
Protocol: 4.25 and Later
Unreal version: 2.7.1
Live Link, and ARKit plugins are enabled.
I have also tried the default port and to type myself the port 11111.
I have also check if the port was used, which is not the case.