Energy measurement problem

[Dominik606]

I have a 17-module installation and I'm having trouble with the energy output of three modules, with an average output of around 2.5 kWh. The remaining three modules show values ​​below 0.2 kWh. I should add that these three modules are on a separate communication loop, and the connection sometimes drops, but the power graphs have the same shape as the other modules. Furthermore, the energy output on the Tigo website is correct.