Shelly 3EM /Shelly Plugin

Hi,

I have a question about the validity of my configuration. I’ve installed the Shelly plugin and have a Shelly 3EM connected to my main meter. I also have several Shellys monitoring a small solar system. These are defined as “Solar Panels” in the Homey app. The Shelly 3EM occasionally shows a negative value on one phase. I’m feeding power into the grid. However, when I read the solar generation from the inverter in the evening, these values don’t match those in the Homey Energy app. What could be causing this?

Thanks