Need product variant attributes chosen before adding product to cart.

Am VERY new to nopC and trying to figure out why I'm able to add a product to the shopping cart in the Store Front without the attributes Size and Color being chosen by customer.  In 'product variant attributes' I've checked the box "is required".  What else do I need to do?  Thanks!!!

Maybe there are values that are marked as Selected?  Or do the products show up in your cart with no values selected?

Yep, that fixed it!

I had added an Attribute called "Select" with "Is pre-selected" marked "true" thinking this would be the default to show on the product page and que the customer to make a selection.  That obviously didn't work.  

So if I just change the "Is pre-selected to false and place it at the top of the Display order it will show up at the top of the list and could be chosen as the color or the size.  Maybe I'm overthinking this.  What do other folks do in this situation?

You hit the nail on the head with your reply, this is my first post and want you to know I really appreciate knowing there's folks out their willing to help!  Thanks.