Glow/Hildebrand MQTT Stopped working with 2023.9 upgrade

I set up my Hildebrand Glow In Home Display to send energy/power readings to Home Assistant using the instructions here https://www.speaktothegeek.co.uk/2023/02/glow-smart-meter-display-and-home-assistant-configuration-tutorial/

It’s been working for months, but when I upgraded to HA 2023.9 today, the MQTT entities stopped working. One of them is

mqtt:
  sensor:
    - name: "Smart Meter: Electric Power"
      unique_id: "smart_meter_electric_power"
      state_topic: "glow/MAC/SENSOR/electricitymeter"
      device_class: "power"
      unit_of_measurement: "W"
      state_class: "measurement"
      value_template: "{{ (value_json['electricitymeter']['power']['value'] * 1000) | round() }}"
      icon: "mdi:flash"

The value of this sensor is now always unknown.

Can you help advise how I can fix this pls?

This was due to network settings becoming mis-aligned - now put right.