Woocommerce / impossible to get product VARIATIONS sales

Woocommerce / impossible to get product VARIATIONS sales

Hi,
Everything's fine with my Skyvia / woocommerce connection, except the fact that it looks impossible to get product variations sales.
I can get product total sales, I can get some product variation informations, but I can't get product variations sales, which is what I need. (for example, in case you're not familiar with woocommerce, XXL, XL and L are variations of the black shirt product).

Any idea and/or help about it ?