can't get energy usage with fibaro wall plug and vera

I’m using vera 7 and have a fibaro wall plug connected.
the energy section recognized the wall plug (I know this because in current usage tab, I can select “wall plug”), but it always states 0 usage, although I have a lamp wired to the wall-plug for weeks now, and it has been on a lot.

any idea?


Same for me. Any hints on this?