Odd behavior of statistics when summing up two sensors

Hi, I have two sensors providing peak and off-peak values
When I set them out in a statistics graph they exactly show as it is
However, if I add them up then statistics do (imo) odd things…does anyone maybe have an explanation?

Sensor 1

Sensor 2 looks the same only different kWh values

Individual stats graph

I created a sum of both

      - name: "Linky Energy Total"
        unique_id: Linky Energy Total
        device_class: energy
        unit_of_measurement: kWh
        state_class: total_increasing
        state: "{{ states('sensor.linky_bbrhcjb')|float(0) + states('sensor.linky_bbrhpjb')|float(0) }}"
        availability: "{{ is_number(states('sensor.linky_bbrhcjb')|float(0) + states('sensor.linky_bbrhpjb')|float(0)) }}"

and this looks like:

What it seems to do is to pick the meter value at points and then continues (as expected) with total increase and then jumps again…but not every day

Change this:

availability: "{{ is_number(states('sensor.linky_bbrhcjb')|float(0) + states('sensor.linky_bbrhpjb')|float(0)) }}"

To this:

availability: "{{ states('sensor.linky_bbrhcjb')|is_number and states('sensor.linky_bbrhpjb')|is_number }}"

Or, preferably, this:

availability: "{{ has_value('sensor.linky_bbrhcjb') and has_value('sensor.linky_bbrhpjb') }}"

Thanks, will try this out a bit, additional info…the 2 jumps you see are at around13:00 and around 20:00 …and I restart HA ervy dat at 01:00 …without jumps…hence I find this odd, might it be that the entity gets disconnected from the meter?

Not sure, your template sensor should update whenever either of the source sensors (linky_bbrhcjb or linky_bbrhpjb) updates.