SAP B1 ServiceLayer JournalEntries missing values when applying filter

Hello,

If I am requesting JournalEntries with id for example JournalEntries(X) I get full object with CashFlowAssignments

but if I send request someting like this - JournalEntries?$filter=JdtNum gt 3655

CashFlowAssignments are missing from response body.

Is this bug? What can be causing this problem?

Regards