Woocommerce product attributes not copied with MS content copier

Hello,

when I copy products of one site to another, everything except the product attributes are copied. Do you know why?

You can see the copied product here: http://150501riva.bflow-webdesign.com/krollenergy/produkt/lucid-arena-pro/

Only the attributes that were already manually created on this page were copied but without the values.