@cloudhigh yes indeed thats me. When i edit my question above i had afterwards the idea that it could maybe be an issue with WPML or that they would know.
EDIT: WPML suggested to set everything on minimal setupt to see if it relates with plugin / theme but it doesnt relate as we saw.
As the variatons are working on the pages of the translation, and the number of variations showed is also correct, it indicates that it could be an issue in a woocommerce php concerning showing this one? But as i am even not an intermediate in coding, its difficult for me to evaluate this