To resolve this issue:
1. Navigate to Manage Feeds > edit
2. Open the advanced command box found near the bottom of the page
3. Within this box, enter the following:
set attribute_granularity to 0
4. Click Update and then Get Feed for immediate changes.
It appears that the “WooCommerce Google Product Feed” plugin creates “age group” and “gender” attributes with value of “default” within the WP database. Even after this plugin is disabled, our plugin still detects these values. To tell our plugin to “stop looking for additional attributes”, enter the above command.