why GL Distributions are not created for Imported invoices ?

Payables Application , R12.2.9

Hi Group ,

 In Oracle R12.2.X Payables (DEV ) we are importing the Invoices data from a csv file , using a custom program to validate the GL accounts , line amounts, Suppliers etc. data and by invoking the Payables Import . It created the Invoices and Invoice lines but NOT GL Distribution lines for the Invoice line which for information sake here as Default GL account correctly populated . Also sets of books data is proper .

And very similar another old import program which is already running in our QA/ Prod instances , just the same type of data , but for different vendor may be , is creating GL distributions for created AP invoices properly. But in our DEV system both program new and the old imports not creating GL Distributions .