When you have multiple invoices in queue with a billing schedule, it is by design that BQE CORE only creates one invoice at a time. Each invoice must be created separately, even if part of the billing schedule. Projects with a billing schedule are added to the Invoices screen automatically if the billing date falls during that billing period. It will also be added to the Invoices screen based on the Reminder Date when set, as long as it is on or before the current date and has at least one time entry during the period before it is generated.