[1.0.0] (solved) Crash launching LAN game on macOS

[TheIndustrial]

When I launch a LAN multiplayer game, the game crashes after ~2 seconds.
I'm on macOS Big Sur (RC 2), I have no mod, and the log file seems to show no error, and macOS crash reports does not notice Factorio's crash.
I have no issue when I host an online multiplayer game neither on solo.
(I don't know if the issue is only when I'm the host, I will try without being host and post an update.)

To reproduce this issue :
1) In "multiplayer", start a new game/load an existing game
2) In settings, tick "LAN"
3) Launch the game
4) After ~2 sec the game crashes (closes without notice)

[Loewchen]

The log does not show a crash, suggesting the app was killed by the os, check the macOS logs.

[TheIndustrial]

Thanks for the hint, I actually did not setup Little Snitch correctly so it kept closing Factorio's connexion to localhost.