The app does not "pair" with the Roku device. It simply scans the connected network for any Roku device it finds and allows a connection to it. Based on your statement about being on a semi-private network, chances are good that the router has a security function enabled that blocks connected devices from seeing either other. That will stop the app from finding the Roku.
The other issue might be the IP address range they are using within your network segment. Roku programmers designed the app to only work if the IP address is within what is considered a Private IP address range. Here is the list of ranges considered Private:
There are three IPv4 private ranges for Class A, Class B and Class C ip address ranges. These private ip address ranges are given below:
- Class A: 10.0.0.0 to 10.255.255.255 (16.777.216 IP addresses)
- Class B: 172.16.0.0 to 172.31.255.255 (1.048.576 IP addresses)
- Class C: 192.168.0.0 to 192.168.255.255 (65.536 IP addresses)
Most home networks are within the Class C range, almost always using 192.168.0.x or 192.168.1.x. But if your network admins used an address range outside these numbers, again the app will not work.
