You probably have some products Blend attribute has “For variation” checked on, and some of them checked off. When you import, WooPOS detects “For variation” difference on same attribute name. The system will append (v) to the name, so we know one attribute is
“For variation”, and another is not. The main reason is that WooPOS “For variation” is on attribute level, while WooCommerce is on the product level.
