I am trying out 3b and here is my code: gist. I am not doing anything unusual and my code passes the test suite.
however, I noticed two things. In logs, the value of message is always 0:
2023/02/26 15:54:25 Received {n1 n0 {"type":"broadcast","message":0,"msg_id":1}}
even in the messages.svg, I can see it only message:0 being passed: