Technical issues with Heroes III.

We recently tried playing with Scorpion through GameRanger and encountered a problem. When it's my turn (I'm the host), the data loading bar fills up very slowly, sometimes freezing at certain values. Sometimes it loads, and sometimes the connection is interrupted. When I pass my turn, everything is fine. We tried switching hosts – now Scorpion was the host, but when I joined, nothing happened on my screen, while the opponent reported that the start button had been pressed and it was stuck at 99%. We tried using Hamachi; the pings were good (~100ms with no packet loss), but the opponent couldn't join my game (there was an error related to the connection). I tested the connection through GameRanger and Hamachi with another player, shpilenger, and everything was fine; turns were passed almost instantly. However, when he was the host, the same thing happened – when I started receiving data, a connection error occurred, and I was disconnected. Technical information: Me: My computer is connected to the router (Port-Restricted Cone NAT Router) on the attic via a local network (DHCP addressing), and the router is connected to the provider via fiber optics. Heroes version: HD mod installed on 4.0 Complete Collection. Opponent: 1) Connected to the internet via VPN. Heroes version: HD mod, version 3.2. 2) Connected to the internet via ADSL, static IP. This is the window Game Ranger displays when I try to join/create a room. In most cases, the game runs without problems, but this issue is happening more and more often. Please advise on what we can do