TRV account derivation on projects PO

Hi

Can someone help with Tax Rate Variance derivation on invoice matched to PO with one of lines having CIP account. We have PO's created with one line assigned to capital project (CIP account as charge account 15110) and another PO line is non project (expense account.as charge 71120 account).Both line accrue on receipt unchecked

When Invoice created with PO matched and tax line entered ($100),system attributes TRV value of $100 to the expense account 71120 of the PO . Expect system to attribute amount $50 to 15110 and $50 to 71120 .

Please share if system considers Asset account to attribute TRV .

Thanks