SLA - Account Derivation Rule not working for Credit Memo

We have quite complex SLA rule for AR Revenue, Credit Memo, chargeback, etc... We not only use different accounts for each invoice types but we derive the channel segment of the GL Account from customer Classification.

I have setup Account Derivation Rule for each invoice types with conditions that look at Bill To Customer Classification and it is working correctly for Revenue, Debit memo, Chargeback, Discount, etc... but not working for Credit Memo.

I setup a custom Account Derivation Rule with a constant CCID for each customer class and setup a condition that match the Bill To Customer Classification, e.g. Value = “101-Sales-CM Account-ClassA” if Bill to customer classification is A, value = “101-Sales-CM Account=ClassB” if Bill to customer classification is B.