Service Manager invoice is not being transferred to AR during Day End Processing. Checking the invoice in Service Manager shows it has a 'SUB' prefix.
This means that the option to 'Consolidate this Invoice' has been selected when the invoice was posted from Document Entry.
You will need to open day end from Service Manager (not IC) and VM and click on the Inv. Consolidation tab. Select one of the options: Consolidate all Sub-Invoices, Select Sub-Invoices for Consolidation, or Select Sub-Invoices for Consolidation by Customer. Run the Day End Processing, and the invoice(s) will be consolidated and transferred to AR with a new invoice number.
If the consolidation option was selected in error, and the number of the invoice in AR being different from the invoice number in Service Manager is a concern, you will need to credit out SUB invoice in Service Manager and re-issue new invoice to get the correct numbering. Ensure 'consolidate invoice' is not selected when posting invoice.