Can't connect two computers in LAN via AdHoc Multiplayer (MHFU)

[gid15]

I've made another test with JPCSP v0.6 2958:2982, and attached the logs.

What I did is that I started up the game on "Log-2", and went to the Gathering Hall, but didn't choose a Hall number (Lobby). I went here with "Log-1", and I tried to get into the Hall at the exact same time on both PC's.

What happened is that I couldn't see anyone on "Log-1", but on "Log-2" I saw another name (it was the same, I use the same savegame and files, but it shouldn't conflict based on prior testings with "2 emus 1 PC"). Just the name, no other information, character model...etc was working.

This was on a real LAN, I didn't test it on Tunngle (yet)

BTW Log-1 is my PC, Log-2 is my bro's PC.

It looks like the PC from Log-1 is not receiving anything, not a single message from PC 2.
Is there maybe a firewall on PC 1 blocking all the requests?

Note: PC 2 is correctly receiving messages from PC 1, but the other way round doesn't work.