Bcc not working on bulk invoice send

Am I missing a setting?

When I send an invoice using the "Send now" button, it populates the BCC box with whatever is configured in my global BCC settings. When I select half a dozen invoices from the list and click the "Email" button on the invoice list page (/accounting/sales/list-sent), it sends the email to the client but does not send the BCC.

Up until last month, this only BCC'd ourselves so we had a contingency copy of our invoices.. we've now taken to integrating Trust Pilot in to our invoice process, and as such clearbooks isn't sending out the invitation triggers.

If anyone has a solution to this, that would be great.. If it is indeed a bug, a fix would also be great.

Thanks PG