ZeroMQLink error

[ddph3dg]

I'm using version 12.3 of wolframscript and when I try to run the server script I get the following error:
Argument ZeroMQLinkPrivate$AsyncState[Task] is not a valid AsynchronousTask object

I'm not an expert with connection functions but if I just copy paste the script and run it in a REPL and ignore the last couple of lines about ZeroMQ and Async I can use a client. What exactly is the purpose of this last bit?