Negative values in untracked consumption when Heating or Warm Water consumption is recorded

[Vaiperu]

Does anyone have any experience with this issue? I am still a HA noob, and maybe I am doing something wrong ...

I am reading the house energy with a Shelly 3em and I integrated my flexoTHERM with solar panel (for water).

Some days when there is like a 1kWh spike for heating, there is a small negative spike of unknown consumption.

It feels like some energy from the solar panel or the environmental gains is not tracked properly.