SSM agent - supposedly race conditions with websocket connections

I'm trying to open a websocket connection with an SSM agent running on my EC2 to fetch container logs

locally it works great,I open the ws connection and get the logs as I wanted.

my issue is when I deploy my server on another EC2, then I don't get any "new" message from the ws connection, I assume there is a race condition (?) between the init phase and the communication part

I do get the a response after the init part in the "open" handler :

ws listeners :

const command = `sudo docker logs $(sudo docker ps | grep -i '${taskFamilyName}' | awk '{print $1}' | head -1) -f --tail 0\n`;

ws.on("open", () => {
  init(ws, {
    token: TokenValue,
    termOptions: termOptions,
  });
 //  I assume this is the 'problematic' part
  sendText(ws, textEncoder.encode(command));
});

ws.on("message", (event) => {
  let agentMessage = this.decode(event);
  this.sendACK(ws, agentMessage);
   ... 
});

examples of the agent responses (decoded) :

  headerLength: 116,
  messageType: 'output_stream_data',
  schemaVersion: 1,
  createdDate: 1681738240767,
  sequenceNumber: 0,
  flags: 1,
  messageId: 'xxxxx,
  payloadDigest: 'xxxxx,
  payloadType: 1,
  payloadLength: 16,
  payload: Uint8Array(16) [
    27,  91,  63,  49, 48, 51,
    52, 104, 115, 104, 45, 52,
    46,  50,  36,  32
  ]
}

-> which is 'sh-4.2$'

and an acknowledge after I send my command (i assume ?) :

{
  headerLength: 116,
  messageType: 'acknowledge',
  schemaVersion: 1,
  createdDate: 1681738242743,
  sequenceNumber: 0,
  flags: 3,
  messageId: 'xxxxx',
  payloadDigest: 'xxxxx,
  payloadType: 0,
  payloadLength: 175,
  payload: Uint8Array(175) [
    123,  34,  65,  99, 107, 110, 111, 119, 108, 101, 100, 103,
    101, 100,  77, 101, 115, 115,  97, 103, 101,  84, 121, 112,
    101,  34,  58,  34, 105, 110, 112, 117, 116,  95, 115, 116,
    114, 101,  97, 109,  95, 100,  97, 116,  97,  34,  44,  34,
     65,  99, 107, 110, 111, 119, 108, 101, 100, 103, 101, 100,
     77, 101, 115, 115,  97, 103, 101,  73, 100,  34,  58,  34,
     53,  49,  53, 100,  99, 101,  49,  56,  45,  97,  54,  55,
     56,  45,  52,  51,  57,  53,  45,  57,  50, 100, 102,  45,
     53,  55,  52,  57,
    ... 75 more items
  ]
}