Invoice quantity more than delivery quantity.

Process:

Sales order-->(va02)header billing plan(both down payment & close invoice)-->(VF01)down payment request-->outbound delivery --> vf01-->J1IIN

Problem:

My (second/subsequent)invoice is picking billing quantity greater than delivery quantity when invoicing w.r.t Sales Order.

When I go to VF01, after creating the sales order and delivery for the first invoice it picks the quantity correctly but for the second invoice it is picking the quantity more than the delivery quantity.

Example:

Sales order quantity = 35 pcs

First Delivery = 3 pcs

First invoice = 3 cs

Second Delivery = 5 pcs

Second invoice = 8 cs

Configuration:

Item Category billing relevance = I

VTFA - item level, billing quantity = B