Same product in multiple Item line of a Quote/Invoice/Sales Orders cant Update by API

Same product in multiple Item line of a Quote/Invoice/Sales Orders cant Update by API

Hi,

In a Quote there are multiple item line product (Same product Code are in multiple item line) in a Quote .


If this Quote I want to update by API then this Quote is updated but not the Item line Products (Product details). Whats the reason?

Or if have the solution then plz send me.