Google Analytics Enhanced E-commerce product_variant not mapping to Google Analytics Beacon

[VT]

Hello, I'm using the Google Analytics Enhance E-commerce settings and am having an issue with variables not mapping to the Google Analyics Beacon. 

The UDO populates the following variables:

product_id

product_name

product_brand

product_category

product_variant

product_price

product_quantity

However I'm only seeing the following in the Google Analyics Beacon:

• pr1id
• pr1nm
• pr1ca
• pr1pr
• pr1qt

product_brand & product_variant aren't getting mapped.

How do I resolve this?