Energy usage for one device is wrong

I have several (Sonoff) power monitoring plugs. On one of them the energy dashboard always shows a value that’s too high by factor X. But the settings are the same for all plugs. I’ve already removed the plug from the energy dashboard and added it again.

For yesterday it shows 9.5 kWh for example, but actual consumption was only 1.4 kWh

Does anyone have an idea how to find the cause.

Dyson is ok


3D printer is not ok


I added another identical plug yesterday. Here too, the Energy Dashboard is calculating/displaying something completely wrong. But the sensor values from the device itself are correct/plausible.

If it weren’t for the one Dyson plug showing correctly in the Energy Dashboard… but why is one correct and two wrong when they all have the same settings …