Ever since we patched our BDS to 1.19.31, we haven't been able to connect to the hosted game over the LAN. In debugging, we see that it connects to the server and then Wireshark shows malformed packets. 

Things We've Tried

Spin up a new 1.19.31 world on the server: Ensuring we aren't trying to connect to a corrupted world file, so starting new - can't connect. We see the server as a joinable server under LAN games but get connection timeouts. From one client, we tried connecting under the Add Server option and that also got connection timeouts.

Intentional wrong server version on the LAN: can get the error of an outdated version, so no problems communicating there

Connecting from our clients to another player's shared game (over the Internet, non-LAN, non-BDS) with a 1.19.31 client: Works fine, so looks like it's isolated to BDS.