Shooter Game Example don't work by network

Hello!
I downloaded Shooter Game Example (project), then open it in version 4.8. Then build the project in windows standalone 64 bit. If I run at home, create a server and run even send one copy, the search servers see my server. And if my friend create a server (or I) to another computer, the search server does not find anything. What could be the reason? PS: I have opened all the ports.