Can direct connect to lan server but cannot see it on server list

My brother is able to connect to my server via direct connect in the IP:PORT format but we would like to know how to get it to show up on the servers list instead as that is less tedious then getting the port and typing it in every time, I searched but I could not find anything like this.

Java is unblocked on both of our PCs and neither of us have Antivirus software