Hi,
I recently bought a 3EM and face a similar issue. Live figures from 3em look fine but if I down load the history values via .csv file they are much smaller and do not match at all the live values.
I would like to have some daily graphs of my energy usage but file download delivers wrong values. Trying to get my 3em into my local WLAN it hangs up (but worked fine for my shelly plug S with good live figures and stats in https://home.shelly.cloud/ but 3em stays offline). I tried already all from reboot, reset, .... only fixed IP I did not try yet.
Any solution available?
As live data is fine on my EM3 wlan are there any easy and free tools/apps to stream live data to create the graphs? Kalougear you mention you use home assistant with mqtt, would this be something for my use case?