Two things stand out to me on the screen shot for your Part Set-up Screens:
- Why is your Costing Lot Size set to 0.00? You should make that at least 1.00
- Why is your Buy To Order checkbox not checked in Default Site Parameters?
It’s been a long time since I’ve dealt with E9; but also wondering if part should be checked as Non-Stock as well.
Typically speaking, the Site Parameters should reflect how the part is to be processed. By having the mismatch between the part record and how the PO/Sales Order were set-up; it might have prevented Epicor from going through the proper costing logic during the transactions.
Of course, various versions of E9 were a bit buggy, so I would play around with different configurations in a test database until the transactions occur the way you want them to. Sometimes it’s a bit of trial and error; but I have always found that if the Part Record isn’t set up properly, you’ll commonly find transactions not behaving properly. Posting Rules typically rely on both Configurations and Transaction types in their logic. I have also discovered that sometimes Posting Rules themselves need to be adjusted. However, verify that the parts, purchase orders and sales orders are configured properly, and transacting properly, first, before even looking into possible issues with the posting rules.