One Shipment with 2 different Sales Orders are splitting the AR invoices for Freight lines

Scenario 1:
One shipment with 2 different Sales Orders it should create 1 invoice for each Sales Order which includes the freight lines.

But it is creating for 4 invoices in total ⇒ 2 invoices for material lines (one for each sales order) and 2 separate invoices for freight lines for each sales order.

Problem statement:Freight lines are seperated from material lines and being put in separate invoice.

Other Scenarios are working correctly.

Scenario 2: 1 SO and 1 Shipment number which is creating single AR invoices including Freight Line.
Scenario 3: 1 SO and 2 Shipment numbers which is creating single AR invoices including Freight Line.

We need to know why the Scenario 1 is creating the separate invoice for Freight line.