If you are using "Generic Child Variant" custom field, then you should have the "Parent Product Is order-able" option DISABLED.
So, the "parent product" will be removed from the dropdown, and only the "child products" will appear in the dropdown selection box.
You will get 2 benefit with this:
- The parent product will be hidden from the dropdown, which avoid the duplication
- If you have some stock number in parent product and if it becomes out of stock, even though there are some stock has left in child products, that particular product labeled "out of stock" in category browse page. It is because only the parent product is taken into account to check if the product is "out of stock" or not. This is also how Virtuemart was designed but there is no label in the category browse page that indicates if any product is out of stock or not. But our VM Template has it in category browse page, so I personally advice not to use that custom field at all if you care about the "stock info".
You should use the other custom field type, which is "VM Custom Stockable Variant" plugin. That custom field also works with Child Products and let you keep the stock number track. (like, if any child product is out of stock, and if it is selected from dropdown, the add to cart button transfers to "notify me" button automatically so buyers can't add it to cart.)
I hope I am clear enough.
Cheers.