Returning Socket.connect/2 error to phoenix.js

Hi everyone

Just updated phoenix.js to latest where the .onError signature seems to have changed
Previously, I was just getting the status code as a string. Now I’m getting an object with shape

  isTrusted: false,
  message: "Expected HTTP 101 response but was '[Status Code] [Status Code Label]'"

Not sure exactly what happened.
That being said, I also discovered since I last updated my deps that Socket.connect/2 return value also got updated, now allowing you to return {:error, term} instead of just :error

I tried doing just that, as well as implementing the Endpoint websocket error_handler as instructed here, however, I get the same error object as above (and yes I restarted the server)

  conn |> Plug.Conn.send_resp(401, "this string never makes it RIP")

returns err on the js client socket instance socket.onError(err =>

  "isTrusted": false,
  "message": "Expected HTTP 101 response but was '401 Unauthorized'"

The only part that changes in the response is the string following ... response but was

Any ideas?

NB: Currently circumventing with