Hosting a game with Hamachi

[Sunrider]

Hey y'all, me and a friend have been trying to play together, unfortunately, I am not able to open ports (I am currently fighting with my ISP over this) however, in other games we've found a workaround to openning ports by using Hamachi. However, on IL-2 BoX we have not been able to connect, even if we're on Hamachi.
 

We are able to ping each other on Hamachi so I believe we're ok on the firewall side of things, he can also see me on the server list but he is not able to connect, we get error 10019 and it boots us right back to the server list.
 

I've tried everything I've seen online to no avail, so any help is appreciated!

[Sunrider]

Update: We've changed to ZeroTier, however, we are still not able to join each other, I've also downloaded Dserver and created both a local server and an external one, however, my friend is still not able to join (Error 10019). We can ping each other no problems and our firewalls were down when we were trying to join, I sincerely do not get what's wrong.