Me and my friend want to play Minecraft together on the same WiFi. He has a Windows 10 computer and I have a Mac. At first, opening to LAN would not show up at all. Then I found a way to prefer IPv4 using:
_JAVA_OPTIONS=-Djava.net.preferIPv4Stack=true /Applications/Minecraft.app/Contents/MacOS/launcher
This would make my friends place show up on my screen, but my friend would not see my place when we enabled our open to LAN at separate times. I tried disabling my firewall and it would still not work. When I try to connect to my friends place, I get the error
io.netty.channel.connecttimeoutexception connection timed out.
When my friend tried to direct connect, he would get the same error. Any help is appreciated. We are both on the same Internet right next to each other.