@digibandit Thanks for reporting and your right it should be there but the problem is the way we handle redirects globally in ITFLow. We used to have the option in invoice details to delete but it would redirect back to the deleted invoice and stating the default nothing to see here page. We removed as it was reported as a bug with UX.
Also technically we could just have it redirect back to invoices but there are 2 invoice views one in client view and one in global view and if they had any filters set it would be lost. Its a double edge sword which I havent figured out a good fix