PON Private WiFi Network: 172.30.x.x:3000 | protocol blocked?

[wwwhtml]

This weekend I installed rocket.chat server on a MacOS Sierra (http://172.30.x.x:3000), and while connected to the PON Private WiFi Network clients couldn't connect to it.

As I recall, I was able to ping from the server to client, and vice-verse.
Is it possible that the Port 3000 or rocket.chat Protocol maybe being blocked|in-use?

I connected the rocket.chat server on a different router wifi network and Client connected w/o problems.

Thanks.