Product: NetSuite 2021.2
The Invoice Billable Customers page is no longer grouping charges by Customer, instead it is grouping it by Employee.
Navigate to Setup > Accounting > Invoicing Preferences
Click Charge tab
Remove Employee in Group Charges by field
Group Charges By - Use the drop down list to chose the field you want to use to group charges on invoices. When you generate a customer invoice, all charges with the same information in the selected field are combined on a single line on the invoice.
When you bill charges on the Invoice Billable Customers page, a separate invoice is created for each grouping. The invoices created include line items for each grouped charge.