Unit selling price is not getting calculated automatically when unit list price is overriden using o

Hi Experts,

We have a requirement where we will pass our own unit list price which is different than unit list price defined in a price list setup. We want to override  list price and selling price should be calculated on overwritten unit price.

I am using oe_order_pub API and I can see list price in sales order form but unit selling price is null.

We have set up profile OM: List Price Override Privilege on application,user and responsibility level. If I overwrite list price in sales order form and click save, It automatically calculates selling price by applying all automatic modifiers by considering overwritten unit list price. But it is not happening using API. Can someone suggest what I am missing here.