How to subscribe to all topics/messages using NodeJS mqtt, emqx

I am writing an MQTT subscriber in NodeJS using the mqtt package. The goal of this subscriber is to receive all messages coming to any/all topics but looks like the subscription to # (subscribe to all topics) does not seem to work. But when I replace # with an actual topic name it seems to work fine. Not sure why it is not working.

PS: the broker I am using is emqx.

Here is the code below.

const mqtt = require('mqtt');const TOPIC = '#';const HOST = process.env.HOST || 'localhost';const PORT = process.env.PORT || 1883;const USERNAME = process.env.USERNAME || 'username';const PASSWORD = process.env.PASSWORD || 'password';const PROTOCOL = 'mqtt';const clientOption = {port: PORT,host: HOST,username: USERNAME,password: PASSWORD,protocol: PROTOCOL};const client = mqtt.connect(clientOption);console.log(`Connecting to mqtt://${HOST}:${PORT}@${USERNAME} topic:${TOPIC} ...`);client.on('connect', function () {console.log(`Connected!`);client.subscribe(TOPIC, function(err) {if(err) {console.error(err);} else {console.log(`Subscription to ${TOPIC} successful.`);}});client.on('message', function (topic, message) {// message is Bufferconsole.log(`Incoming message to topic = ${topic} ...`);console.log(message.toString());console.log('Preparing outbound message');const outboundMsg = {...message, source: topic}console.log('Outbound message below');console.log(outboundMsg);});});