Duplicate Server Problem

When I start up my server, it appears two times in the server list on GMOD. How do I fix this?

Don’t. Better chance of someone joining your server. In fact, that would be a funny exploit. Just spam the gmod server list with shitloads of random servers.

Lol, good idea, but I still want to know what can cause it.

Probably some bug in the master server, just leave it be and I’m sure it’ll go away soon.

If it’s a server on your PC then it appears twice, once as a regular server and once as a LAN server.