"Accrue on Period End" then the Invoice distribution uses the PO Expense Account why ?

Summary:

we are using "Accrue on Period End" and "Accrue at Receipt" If you set the PO to "Accrue on Receipt" then the Invoice distribution uses the Accrual Account. which is normal but If you set the PO to "Accrue on Period End" then the Invoice distribution uses the PO Expense Account.

So my question how system will handle this expense account is it reversed in the next period ? what happen when we run "create unvoiced receipt accruals process" which should create accruals is this expense account will affected or not ?

Content (required):

Version (include the version you are using, if applicable):