One business unit multiple legal entities Issue - defaulting correct legal entity

Summary:

Hi all,

We have three legal entities and one business unit across procure to pay cycle. Each legal entity has it's own bank account. Client is using invoice imaging IDR functionality and gets both PO matched and Non PO matched images sent to IDR.
There are suppliers with one site/address sending invoices to more than one legal entity.
When the invoice is received from suppliers sent for multiple legal entities via IDR, Legal entity is defaulting based on the supplier site liability BSV. Liability can be updated using automatic offset option based on the expense account. Problem is with the legal entity is not getting updated based on the expense account BSV and it leads to incorrect legal entity.