How can I get my Template Sensors to update?

Hi,
I have these sensors defined in my configuration.yaml

mqtt:
  sensor:
    - name: rwg_tx_quota
      unique_id: "tx_quota"
      unit_of_measurement: "bit"
      state_topic: "quota/tx"
      
    - name: rwg_rx_quota
      unique_id: "rx_quota"
      unit_of_measurement: "bit"
      state_topic: "quota/rx"
      
template:
  - sensor:
      - name: "rwg_total"
        unit_of_measurement: "GByte"
        state: >
          {{ (((states('sensor.rwg_rx_quota')) | float + (states('sensor.rwg_tx_quota')) | float ) / 800000000) | round(3)}}
               
      - name: "rwg_balance"
        unit_of_measurement: "GByte"
        state: >
          {{ ((20.00 | float) - ((states('sensor.rwg_total')) | float)) | round(3) }}

The mqtt (rwg_tx_quota & rwg_rx_quota) update in real-time. However, the template sensors (rwg_total & rwg_balance) only seem to update on system restart.
I have tried adding update_interval: 60s, but that is reported as an error?

Logger: homeassistant.config
Source: config.py:592
First occurred: 09:11:44 (2 occurrences)
Last logged: 09:24:45

Invalid config for 'template' at configuration.yaml, line 44: 'update_interval' is an invalid option for 'template', check: sensor->0->update_interval

Any thoughts…
Regards, Martin

Please provide sample values

Is this what you mean?
image

If not, let me know how.
Regards, M.

No, actual values, to test your templates (in text, please, not pictures)

Sorry Chris,
Can you show me how?
Regards, M.

That

image

Thank you Chris. So values cut 'n paste from Developer Tools are:
sensor_rwg_tx_quota = 11476485
sensor_rwg_rx_quota = 308853558

Any help?