Can you login to the instance experiencing the issue as the same user that DPA users for monitoring and run an explain plan for the query in question?
Any errors reported doing that?
The query has an unqualified table name, so the Live plan will try to use your DPA user as the default schema name for the table i.e. <DPA_user>.OA_CUSTOMER_DTL which (apparently) does not exist.
I don't have Oracle, but when you do a Live Plan for other DBMS you may get prompted for a schema name - use the appropriate one and it should work.