I've been having this problem for quite some time now and I am uncertain of what the cause of the problem is. I've been trying to host some Minecraft modpacks and trying to open it to LAN for my friends to join, but they couldn't connect onto it. I've noticed that whenever I open my world to LAN, I always get a 4-digit port number which seemed off because whenever my friends would have to host it, they always get 5-digit port numbers which seem to work. I am not sure if this is the cause of my problem, but I have a good feeling that it might be. I don't know how to fix this issue, so any help would be much appreciated.