Custom trigger on view is not working

We just upgrade to R12.2, created a new simple DB trigger on view, but seem this DB object cannot be triggered.

After that, we compile the trigger directly on table, it is work. And then we drop the trigger on table, and compile once again on view, it is work too. I would like anything wrong with the custom DB object?

Attached as below for reference.

CREATE OR REPLACE TRIGGER APPS.XXPO_PARENT_REQ_LINE_ID_T2

  BEFORE INSERT

  

 ON "PO"."PO_REQUISITION_LINES_ALL#"   FOR EACH ROW

WHEN (

NEW.REQUISITION_LINE_ID IS NOT NULL AND NEW.PARENT_REQ_LINE_ID IS NULL AND NEW.ATTRIBUTE15 IS NOT NULL