After posting purchase order prepayment invoices, the attachment (usually the invoice PDF) is automatically deleted from the system. I am opening this 'idea' as an attempt to gain traction to fix this regression.

Although a workaround was provided, Auditors are concerned and questioning as to why there is a difference in functionality.

Refer: LCS Issue 830633

Microsoft does not have a plan to fix this at this time, but this is a highly auditable area and very concerning, not to mention confusing to users. Please upvote to get Microsoft to fix this confirmed bug.