HA indicates The following entities have state class 'measurement' but 'last_reset' is missing when adding P1 meter values

[StarWing01]

Today I have rebuild my HA instance and also installed firmware V1.1.0 onto the p1 meter, I have no idea if this was present with the previous firmware.
When adding the P1 meter active and reverse energy:
sensor.zeexxxxxxxxxxxx_totalactiveenergy
sensor.zeexxxxxxxxxxxx_totalreverseenergy
to HA energy dashboard, I receive:

Last reset missing
The following entities have state class 'measurement' but 'last_reset' is missing:

The P1 is connected to HA by MQTT.

[dav1dBoy]

Today I have rebuild my HA instance and also installed firmware V1.1.0 onto the p1 meter, I have no idea if this was present with the previous firmware. When adding the P1 meter active and reverse energy: sensor.zeexxxxxxxxxxxx_totalactiveenergy sensor.zeexxxxxxxxxxxx_totalreverseenergy to HA energy dashboard, I receive:

Last reset missing
The following entities have state class 'measurement' but 'last_reset' is missing:

The P1 is connected to HA by MQTT.

Hi,

This message from Home Assistant is actually related to how the sensor metadata is defined, not to a malfunction of the P1 meter itself.

The Home Assistant Energy Dashboard has strict requirements for energy sensors:
• Sensors with state_class: measurement must provide a last_reset timestamp.
• Sensors that represent a continuously increasing total energy counter (like a smart meter’s total import/export values) should instead use state_class: total or total_increasing, in which case last_reset is not required.

The entities
sensor.xxx_totalactiveenergy and
sensor.xxx_totalreverseenergy
are cumulative energy counters by nature, so they are expected to be exposed as total_increasing, not as measurement.

When these sensors are published via MQTT with state_class: measurement but without last_reset, Home Assistant correctly reports the warning you’re seeing.

If you control the MQTT discovery configuration, the recommended fix is to publish these sensors with:
• device_class: energy
• state_class: total_increasing
• unit_of_measurement: kWh

No last_reset is needed in that case, and the sensors will be accepted by the Energy Dashboard.

So in short: this is a metadata classification issue rather than a firmware or MQTT transport problem.

Best regards,
David