Emails Not Added for Orders Placed in Back-End

Hello, we process a lot of orders through the admin area of Woo Commerce as we receive a lot of checks for a certain product. When we add orders in the back-end, they do not import into MailChimp. They do for all credit card orders though. We have tried different scenarios such as changing to processing, complete, etc but nothing works. Any help is greatly appreciated. Thanks for great plugin.

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