price filter issue with variable products woocommerce

Hi,

I am using woocommerce 2.6.1 and i have an issue with the woocommerce price filter in combination with a variable product containing multiple variations. And a variable product containing 1 variation

if you look at this item
https://www.mijnparfum.nl/parfumerie/zijnparfum/tommy-hilfiger/tommy-hilfiger-tommy-edt/
a variable product with a 100ml and a 50ml variation.

This item shows up only when i place a max price of 31 euro and more.. So the filter ignores the 50ml price value of 27,85 euro.. DOES NOT WORK:https://www.mijnparfum.nl/-parfumerie/zijnparfum/?max-price=28 / WORKS:https://www.mijnparfum.nl/-parfumerie/zijnparfum/?max-price=31

Another issue i have is with a variable product where i only have 1 variation. Example: https://www.mijnparfum.nl/parfumerie/zijnparfum/tommy-hilfiger/tommy-hilfiger-tommy-edc/ this product doesn’t show up at all after placing the filter on 34 euro or more… https://www.mijnparfum.nl/-parfumerie/zijnparfum/page/2/?max-price=34

Strange thing is, when i convert it to a simple product, it does show up in the filter correctly