Agent cannot receive workflow item in SBWP

Dear all,

We are using PO release workflow. And implemented enhcement M06E0005 Role determination for release of purchasing documents to determine agents by addon code.

For a certain PO, it has 5 approvers, all of them can release this PO.

In SWI6, workflow log, "Agent' botton, it shows all of 5 approvers are agents.

But in SWI5, workitem does not in approvers A B's' SBWP.

In table SWWUSERWI, the field 'Indicator: Entry has no Relevance to Selection' of a approver A B is X(not relevent).

No ST22 dump, No trfc error.
Please suggest.

Richard