Internal order settlement to cost center

Hello

During settlement of internal order(A) to cost center(B) using KO88,it is creating an accounting document as below:

Dr Expense account --  cost center (B)

Cr Expense account -- there is no internal order or cost object credited.

However the controlling document has the right entry credit the internal order and debit cost cneter..through costelement defined with internal settlement 21.

Please advice why in accounting document in the credit entry i cannot see any cost object.

Thanks.