Partner Generated Billing (PGB) only runs on the current and previous month (if AWS updates the previous month's bill) at any given time.
If you have made changes to your customer's AWS Account assignments in their Billing Block and would like to have these changes reflected in past months of the customer level reports, then the CloudHealth Support team will need to regenerate the past month's bills.
Please confirm in your ticket which customer this is in relation to and which months, in particular, you would like to have regenerated to reflect the changes.
Once our Support team has triggered a task to regenerate these bills, you can expect to see the customer level reports updated within 24-48 hours.
Be advised that this may change the costs that appear and result in reporting data no longer matching with invoices previously issued to customers for those historical months.