Newbie problems with first MQTT configuration and NODEMCU with Tasmota

Hi, I’m trying to setup MQTT on my Hassio setup on raspberry pi.

I keep getting these errors in my MQTT broker addon log:

[INFO] Setup mosquitto configuration
[INFO] Found local users inside config
[INFO] Initialize Hass.io Add-on services
[INFO] Initialize Home Assistant discovery
[INFO] Start Mosquitto daemon
1542745522: mosquitto version 1.4.15 (build date 2018-03-04 15:35:59+0000) starting
1542745522: Config loaded from /etc/mosquitto.conf.
1542745522: *** auth-plug: startup
1542745522: ** Configured order: http
1542745522: Opening ipv4 listen socket on port 1883.
1542745522: Opening ipv6 listen socket on port 1883.
1542745522: Opening websockets listen socket on port 1884.
1542745522: Opening ipv4 listen socket on port 8883.
1542745522: Opening ipv6 listen socket on port 8883.
1542745522: Opening websockets listen socket on port 8884.
1542745522: Warning: Mosquitto should not be run as root/administrator.
1542745522: New connection from 192.168.1.50 on port 1883.
[WARN] Not found "unique_login_name" on local database
1542745650: Socket error on client <unknown>, disconnecting.

Where unique_login_name is my user login as configured in addon config:

{
  "logins": [
    {
      "username": unique_login_name,
      "password": "!secret mqtt_password"
    }
  ],
  "anonymous": false,
  "customize": {
    "active": false,
    "folder": "mosquitto"
  },
  "certfile": "fullchain.pem",
  "keyfile": "privkey.pem"
}

similarily in my configuration.yaml I have MQTT section as follows:

mqtt:
  broker: core-mosquitto
  username: unique_login_name
  password: !secret mqtt_password

On my Tasmota config, I can see the temp and humidity with no problems but I just cannot connect to the broker on HA because the user is not found on the local database. Here is my tasmota mqtt config:

And below is my sensor config:

sensor 3:
  - platform: mqtt
    state_topic: 'tele/SensorOne/Sensor'
    name: 'Temperature'
    unit_of_measurment: '°C'
    value_template: '{{ value_json.SI7021.Temperature }}'
  - platform: mqtt
    state_topic: 'tele/SensorOne/Sensor'
    name: 'Humidity'
    unit_of_measurment: '%'
    value_template: '{{ value_json.SI7021.Humidity }}'

Any help would be greatly appreciated, thank you.

I don’t know if it has something to do with duckdns and lets encrypt but I can only login to HA through my duckdns domain and not locally.