I uploaded a new feed to Google and get the warnings for MPN and Google Product Category. I have an exemption for the MPN but can't understand why I am getting the warning for product category. I have inserted:

Apparel & Accessories > Clothing Accessories > Baby & Toddler Accessories

from the taxonomy, in correct XML format, into the Default Product Category.

Is there another setting that I am missing? Have latest versions of GMCF and Product Fields. Any help appreciated!