Riemann integral sum daily shows not correct value

My heating integration provides the entities for the current electricity consumption and the daily electricity consumption.
If I now create a riemann integral sum daily with the input sensor of the current power consumption, I should get the same curve as with the corresponding entity.
But here I have a difference, what could be the reason?

You have probably not selected the best method to reduce approximation errors. See https://www.home-assistant.io/integrations/integration/#integration-method

It will never be exactly the same as the sample rates in data sent to HA, vs the sample rate in the controller are different. I’d expect the controller to be nearly continuous whereas HA only receives the data every 5-10 seconds at best.

Use “left” mode as a heat pump is usually on or off.

OK, my information in the start post was wrong.
Instead of the riemann integral sum daily, I have a utility meter.

This shows the increased values.
I don’t have many setting options in the utility meter.

Do you have any idea why this could be?
Here is a picture of the situation.
image