Unable to connect to the MQTT broker: Connection Refused

Hello everyone.
I wanetd to migrate Home Assistant from QEMU Virtual Machine to Raspberry Pi so i installed Raspbian (Buster) on RPi3 and installed Home Assistant supervisor. Installation process is same as was on qemu vm.

curl -sL "https://raw.githubusercontent.com/home-assistant/supervised-installer/master/installer.sh" | bash -s

Then i created a snapshot on QEMU installation and moved that backup file to raspberry pi (/usr/share/hassio/backup) and reverted snapshot. One issue (so far) persisted after that, and that is the log file is filled with error messages like this bellow. on raspberry pi.

2020-05-03 21:35:01 ERROR (Thread-2) [homeassistant.components.mqtt] Unable to connect to the MQTT broker: Connection Refused: not authorised.
2020-05-03 21:35:01 WARNING (Thread-2) [homeassistant.components.mqtt] Disconnected from MQTT (5).

As far as MQTT configuration concerned i only have two binary sensors (mqtt platform) . HA is not supposed to connect to any MQTT broker, so i don’t understand why these messages appear.

Bellow is binary sensor configuration where mqtt is configured.

binary_sensor:
    - platform: template
      sensors:
        garage_door:
          friendly_name: Garazna Vrata
          device_class: door
          value_template: "{{ is_state('input_boolean.garage_door','on') }}"
    - platform: mqtt
      state_topic: "zoneminder/1"
      name: terasa_sensor
      device_class: motion
      qos: 0
      value_template: >-
        {% set object = namespace(found="OFF") %}
        {% for x in value_json["detection"] -%}
            {% if x.label == "person" or x.label == "car" %}
                {% set object.found="ON" %}
            {%- endif %}
        {%- endfor %}
        {{object.found}}
    - platform: mqtt
      state_topic: "zoneminder/2"
      name: gornja_terasa_sensor
      device_class: motion
      qos: 0
      value_template: >-
        {% set object = namespace(found="OFF") %}
        {% for x in value_json["detection"] -%}
            {% if x.label == "person" or x.label == "car" %}
                {% set object.found="ON" %}
            {%- endif %}
        {%- endfor %}
        {{object.found}}

HA version is 0.109.3.
Can anyone help on what is happening here? Where is it trying to connect and why. How to get rid of these messages?

EDIT:
I should probably add that I’m using Mosquitto broker addon. If i disable Mosquitto, these messages do not appear.
This is Mosquito configuration:


logins:
  - username: zm-mqtt
    password: somepassword
anonymous: false
customize:
  active: false
  folder: mosquitto
certfile: fullchain.pem
keyfile: privkey.pem
require_certificate: false