Tax isn't added to invoices in Create Order automations

I run an organisation where we have to send out bulk invoices to pay through Keap.
We run an automation with the Create Order process, and sends the invoice for the selected product in an email.
HOWEVER - even though the product has TAX on it, that tax isn’t automatically added to the invoice.

I’ve raised it with Keap support a number of times, but it’s never been fixed.
Does anyone have a solution for this?