this happens in 1.15.2, restarting game fixes it.
i can confirm: this is completely broken. Mac server, windows 10 client, both connected to dumb 100BASE-TX hub. mac firewall is ON. windows defender firewall is OFF, network type is 'private'. PC can connect to mac OK with 'Direct Connect' host:port, but game does NOT appear in 'Scanning' list. both Minecraft 1.12.2
yeah, i'm also having issues with junction points. literally no other programs i use have an issue with junction points. the old launcher works fine. i see no point in upgrading until this is fixed.
the launcher definitely says "2.0.760" in the bottom let corner. and it's the native (non-java) version on windows,
I can confirm this with 1.11.2.
it even happens if you widen the portals on both sides, or if you change the orientation of one/both of the portals.
this is an EXTREMELY annoying bug since good horses are so hard to find/breed and there's seemingly no way to prevent it happening.
please, at the very least, ensure that the hose is oriented so its head is sticking OUT of the portal, and not into the portal block.
i did use MCedit to remove everything i could from the world in order to find out what it was that's causing it - it's a combination of the mob trap and the strip mine. remove either of those and the problem goes away.
however, the issue also occurs in the un-modified version of the world.
this is because the mincraft.net server is incorrectly parsing the browser header. my browser is sending
and the server is incorrectly interpreting that as Spanish, when it should be responding with English.