Hello Community Users, We just wanted to add to this thread the outcome of this query. The reason why this was happening was because progress invoicing was being used and that was only compatible with the airy style template. Custom invoices cannot be used with that.  We no longer have the custom invoice import option, which was at the time a Quickbooks Labs feature that was in beta.

It was a case of marking the estimate as closed and then manually creating the invoice prefilled with the information from the estimate.

We're just adding this to the end of thread so any future viewers of this query are aware of the outcome.