Similar still happening to me and wife as is happening to Trevinator. Am going to try the Port forward and then the workaround. Will edit if it works or not. We're also trying to play peer to peer.
Edit1: Port forwarding/workaround seems like an undertaking so we tried a few basic things first:
I can ping her fine through cmd.
We updated to the latest update.
Changed compatibility settings to run with admin rights.
Changed wifi settings to private and made sure firewalls were exempting Vintage Story.
-Did not work, lost connection in 5 minutes.
Connected the host to the router with a LAN cable.
This did not work, I lost connection after about 5 minutes.
Going to attempt to port forward.
