PO Receipt not writing to History but is writing to Location Details

Hello,

I have a client, where in what appears to be random cases, some lines of a PO receipts are posting, writing data to IC Location Details, but not to PO History or IC History. In the case I am studying, the first line wrote fine to POHSTH and ICHIST but the second line of the same receipt did not.

Anybody seen anything like this before? Got any suggestions?

Thanks