Overview
This issue is due to ASC sending an order file to Delta which creates a new order but after this the order is amended in ASC and another 'AMEND' file is sent which overwrites the current data.
What to do next
This can cause an issue as editing one line in ASC will overwrite all lines in Delta.
To resolve this follow the below steps:
Go to the location that hold the import CSV files
Using the Windows Search box type * then the PO number
This will show you multiple files. the first filename will contain 'CREATE' and the rest will contain 'AMEND'
Open each file and find the one with the missing data.
Right click on the file and click Open File Location
Drag the file back into the import folder to allow it to overwrite what is currently in the database.