Context: This is a Summer home with very consistent daily power use when nobody is home. Please see the dashboard from HA. Why am I seeing this spiky behavior on some days and no consumption on others?   IAMMETER's own dashboard show consistent daily consumption as expected. It feels like HA is not polling from the meter on a daily basis but rather aggregating the data over several days. 

Could you please share:

• the firmware version of your meter
• the Home Assistant version
• how the meter is integrated into Home Assistant (e.g. MQTT, hacs iammeter ModbusTcp, hacs iammerter http, custom integration)

In Home Assistant, please check the History of the energy sensor on the days with missing data:

• Did the sensor show unavailable or unknown?
• Was the sensor value not updated at all on those days?

I see a gap in this chart, which means the data upload to Home Assistant stopped during that period.

I believe Home Assistant calculates daily energy by subtracting the first kWh value of the day from the last kWh value of the same day. If the upload stops, HA cannot calculate the daily energy for that day. When the upload resumes, it uses the total kWh difference and assigns it as the daily consumption for the day when data resumes.

For example:

• The first kWh upload on Day 1 is 100 kWh

• The last kWh upload on Day 1 is 110 kWh
  → HA calculates the daily energy for Day 1 as 10 kWh

• The first upload on Day 2 is 110 kWh

• Upload stops during Day 2 and resumes on Day 4

• The last upload on Day 4 is 150 kWh

In this case, HA likely uses 150 − 110 = 40 kWh as the daily energy value for Day 4.

I just confirm this with GPT and it also reply to me the similar answer.