I just installed four of these - the UK version. Easy to install using the camera and QR code, they appeard in HA within seconds, with Power, Current, Voltage and Energy.
The only problem: Energy stays at zero.
They have been installed and powering devices for a week and still Enegy is zero. Power is about a constant 65w on each.
Any ideas?
Answer from Eightree - They really shouldn’t market them as ‘with energy monitoring’:
We’re very sorry, but currently the EIGHTREE Matter Smart Plug does not support energy consumption (kWh) monitoring via Home Assistant — only real-time data like power (W), voltage, and current are available at this time.
We understand that energy tracking is important, and we sincerely apologize for the inconvenience. If this feature is critical for your setup, we completely understand if you choose to return the devices.
Luckily you have the important values and from them HA can calvulate the others.
There is a page for the energy dashboard that explains how, but I find using the PowerCalc integration easier to use.
The vendor should have the inconvenience spending ressources updating their firmware to reflect the features advertisered before. 
Any way matter is a lost cause for me
anyways - no ownership and often only limited local control 
Work’around is a utility meter 
