Cannot Make Product Required on Chat Launch

Content

Hello,

I have a requirement to route to different chat queues based on the Product selected.  I have added the Product dropdown field to my chat launch form, but I can't get it to be required.  This field must be required, because with my new rules in place, when I test with no Product selected I am routed to the Default Chat Queue.

Here is the string:

<rn:widget path="input/ProductCategoryInput" name="Incident.Product" required="true"/>

I have tested and am able to make every other field on my launch page required.  The only difference seems to be this widget path, "input/ProductCategoryInput" rather than "input/FormInput".