Fibaro Wall Plug (fgwp102): no energy?

I installed fibaro wall plug in my vera plus and now I see in Devices:

  • Plug: it works correctly. I can switch on/off and get also current power consumption (p.e. 65,6Watts)
  • Plug Meter: well, this doesn’t work: no watts or kWhs shown. I suppose I should add some configuration setting in some place. Any suggestion?

Thanks in advance

As you can see in attached images, Power meter doesn’t report anything (no power no energy).
How did you solve this problem?