NodeRed MQTT node status remains "Connecting"

Defined the MQTT Broker with following parameters:

Server: Port: 1883
Connect automatically is Checked
Protocoal: MQTT V3.1 (Legacy)
Client ID: SJ-node-client
Keep alive: 60
Use Clean Session is Checked MQTT server is running because my devices are sending MQTT messages and they are getting stored in the buckets also. So why can I not connect to the MQTT broker from Node Red?

  1. I saved the Client ID field as blank. That did not change the behavior and the nodes still remained in “Connecting” state.
  2. If “Clean Session” flag is not checked, a value is required in Client ID. What value should be entered in Client ID?