Energy dashboard stats error

i see an error in my energy dashboard stats.
The export energy for one of my two solar system is less than the real value.
In the energy dashboard i see -18.06 for the entity “solaredgePT_export_energy_active” but if i check in the history the difference between midnight and now is about 20 (that is the real value).
Someone can help me solve the problem?

this is the configuration for the entity:

platform: mqtt
    name: "solaredgePT_export_energy_active"
    state_topic: "solaredge/PT_DATA"
    state_class: total_increasing
    unit_of_measurement: "kWh"
    icon: mdi:solar-power
    device_class: energy
    value_template: "{{ value_json.export_energy_active | round(2) }}" 

The energy dashboard only updates once per hour. Compare just after the hour ticks over.