Custom Fields Not Showing in Header Dropdown

I purchased both Woocommerce CSV Import Custom field add-on and the Premium add-on, and have Woocommerce CSV Import installed. When I add custom fields separated by comma under “Custom Fields” they disappear from the text field when pressing save. They then do not show up on the dropdown as cf_customfield when loading the csv to create headers. I tried just entering one custom field with the exact name as the example, and the same thing occurred. Please let me know if there is another step that is not documented anywhere. The fields for premium (downloadable, etc.) are showing up. This is an essentially brand new install of WordPress and Woocommerce, so I don’t see why there would be any issues.

https://www.ads-software.com/plugins/woocommerce-csvimport/