I'm getting the exact same problem. Included the brief internet disconnection when i'm the host (I can hear discord trying to reconnect each time my friend try to join my Yland).
My friend tried to host and launch a map we used to play on. But i couldn't join either.
Joining a friend's Yland only seems to works if it's a new map. Which is a bit annoying since you can't play on the same map and you're always forced to start again.
Dispite that, i'm really enjoying the game. It has so much potential. (But we're a bit stuck if we can't continue on our yland).
output_log.txt
output_log_clean.txt