The "Shelly Z-Wave Plug" driver does not have the power meter capability @bertabcd1234
The Generic one does, so it would work in rule just fine.
Same as the Fibaro wall plug that you got to work. Unless you were trying to use EnergyMeter and not PowerMeter? EnergyMeter is missing from the generic one @bertabcd1234, but maybe the generic driver does not support the energy metering (not all devices report energy use).
You cannot use the wrong driver (such as Fibaro) and adjust the settings. All z-wave devices may use different settings numbers so you could actually be changing unknown settings on the device by using the incorrect mfg/model specific driver.
You can try and scan for the setting using my universal z-wave scanner tool. Here is more info on another thread also regarding a plug that would not work right with the HE drivers
