Doesn't work within group?

If I put simple products that uses minimum quantities and increments in a group, the quantity box on the group page still starts at and increments by 1. It doesn’t add it to the cart, but it also doesn’t give any notice that it didn’t get added or why. Is there any way to get this working?

https://www.ads-software.com/plugins/woocommerce-incremental-product-quantities/