ThingSpeak MQTT: MQTT connection failed. Error Code: -2

[shantanuraoke]

Hi,

As the title mentions, we are facing errors while connecting to ThingSpeak. I have used the startup menu to edit the ThingSpeak MQTT fields.
Additional information :

1. CA Certificate for thingspeak is in a *.pem format that I got from Google Chrome and it is stored in the root directory on the SD Card.
2. I tried following the settings JSON flow to edit the Thingspeak MQTT fields but when I tried to restore the settings from JSON, the startup menu reported an error in reading the JSON file.

I am new to ThingSpeak MQTT and tried following the tutorial on the official documentation which only mentions CA Certificate field. However, the start up menu displays to additional fields:

1. Client Cert Filename
2. Client Key Filename

Could these be causing the issue?