How to avoid creation of separate Invoice for Freight while using Grouping rules on shipment basis?

EBS- Version is 12.2.6

Details:

We are following grouping rule based on shipment basis (multiple shipment no.=multiple Invoices)

We have defined below line ordering & grouping rule to achieve the result.

1) Line Ordering Rule- sequence 1; Transaction Attribute- INTERFACE_LINE_ATTRIBUTE7; Type-Ascending

2) Grouping Rule- Transaction class-Invoice; Optional Grouping characteristics- INTERFACE_LINE_ATTRIBUTE7

Everything is working fine except if Sales order contain Freight, then system is creating separate Invoice for Freight (as per client’s requirement-We’re adding Freight as a separate item at line level while creating SO)

Expectation is freight should be along with the item in the line level in the AR invoice.