Ok looks like the issue is only with T6 Server, I manually created a server by myself and it works.
Just make sure to create in the %localappdata% wine folder, the right server files, the right permissions, etc.
Oh, and use winehq-stable, not staging, as it looks like there are some regressions.
I did a lot of trial&error since I did not know where to put everything but okay.
Edit: Dedicated.cfg must be put under rootgamefiles/main, otherwise is not being read somehow...
Idk why?