While on LAN, I cannot join local server in snapshot

Whenever I join a LAN world with a friend, I log in (she can see my join/leave messages) but the world refuses to load and I either time out or receive these (pictures included) error messages. This happened at least 5 or 6 times before it worked exactly once, we played fine for about an hour, and after a death, it happened again

We play on LAN consistently, so I can only guess it's something in the new update. I apologize we don't have any more information. In the beginning I guessed it could be something with loading chunks, and when I TP'd to her, the issue stopped. However, her character was right next to our spawn when I died, and it happened again so I don't think thats the full cause. She promises that she isn't doing anything out of the ordinary that could cause these errors on purpose