Mill heater integration in HA via official integration not working

Hello!

I am trying already for weeks to set up Mill heater with HA. It seams that I am passing everything that is needed to Cloud, but still heater switched to Heating and then quite fast to Idle. I check in app latter and see that Mill has not consumed any power and as well room temperature is not increasing. I have made Mill heater independent and its still not working. I am really stuck on this matter. As cold weather is closing in I am worried that i will not solve this with official Mill integration.
I have made quite detailed automation with multiple steps and automation dose not have any error. Only issue is with heater.

Do i miss some important actions in automation to turn heater on?

Dose anybody has working integration with Mill Gen3 oil heater?
My automation:

- id: heater_start
    alias: "Heater Start (cheap slots + safeguards)"
    mode: single
    trigger:
      - platform: numeric_state
        entity_id: climate.heater
        attribute: current_temperature
        below: input_number.heater_start_temperature
      - platform: state
        entity_id:
          - binary_sensor.smart_heating_allowed
          - input_boolean.manual_heating_override

    condition:
      - condition: state
        entity_id: binary_sensor.smart_heating_allowed
        state: "on"
      - condition: or
        conditions:
          - condition: state
            entity_id: binary_sensor.heating_slot_active_aio
            state: "on"
          - condition: state
            entity_id: input_boolean.manual_heating_override
            state: "on"
      - condition: template
        value_template: >
          {{ states('sensor.current_electricity_price') | float(0) <=
            states('input_number.price_limit_heating') | float(0) }}
      - condition: template
        value_template: >
          {{ state_attr('climate.heater','current_temperature') | float(0) <=
            states('input_number.heater_start_temperature') | float(0) }}
      - condition: template
        value_template: >
          {% set s = states.climate.heater %}
          {% set last = s.last_changed %}
          {% set seconds = (now() - last).total_seconds() %}
          {% set is_recent_off = s.state == 'off' and seconds < 300 %}
          {{ not is_recent_off }}
      - condition: template
        value_template: >
          {{ state_attr('climate.heater','hvac_action') != 'heating' }}
      - condition: template
        value_template: >
          {{ states('climate.heater') not in ['unavailable', 'unknown'] }}

    action:
      - service: climate.set_hvac_mode
        target:
          entity_id: climate.heater
        data:
          hvac_mode: "heat"

      - delay: "00:00:02"

      - service: climate.set_temperature
        target:
          entity_id: climate.heater
        data:
          temperature: "{{ states('input_number.heater_stop_temperature') | float(0) + 0.1 }}"

      - choose:
          - conditions:
              - condition: template
                value_template: >
                  {{ state_attr('climate.heater','hvac_action') != 'heating' }}
            sequence:
              - service: climate.set_temperature
                target:
                  entity_id: climate.heater
                data:
                  temperature: "{{ states('input_number.heater_stop_temperature') | float(0) + 0.5 }}"
              - service: system_log.write
                data:
                  message: "Mill heater fallback triggered — increased temp slightly."
                  level: warning

      - service: system_log.write
        data:
          message: >
            Heater mode: {{ states('climate.heater') }} /
            Target temp: {{ state_attr('climate.heater','temperature') }} /
            HVAC action: {{ state_attr('climate.heater','hvac_action') }}
          level: info

      - service: logbook.log
        data:
          name: Heater Triggered
          message: >
            Heater started at {{ now().strftime('%H:%M') }}.
            Heater temp: {{ state_attr('climate.heater','current_temperature') }}°C /
            Start threshold: {{ states('input_number.heater_start_temperature') }}°C /
            Stop threshold: {{ states('input_number.heater_stop_temperature') }}°C /
            Override: {{ states('input_boolean.manual_heating_override') }} /
            AIO slot: {{ states('binary_sensor.heating_slot_active_aio') }}

I have found the reason. When I send “hvac:mode: off” heater becomes a brick and its not responding to any further commands from HA or Mill app. Only option to reactivate it is by physically changing its temperature. I don’t know where this issue is coming from, but its a bug that bricks heater.
At the moment i have solved it by replacing hvac_mode: off with lower temperature.