STRANGE Behaviour when submitting Oracle Reports Concurrent Requests - 11.5.10.2

Hello Gurus,

I am facing a weird issue in submitting an Oracle EBS report(.rdf file). 

Below is the problem description.

1. When I submit the report, it goes into running mode.
2. It stays in running mode forever.
3. When we run the same report in non Production environments, report complete instantly.
4. Even the same report runs perfectly well from report designer.
5. All tuning considerations are well cleared. The same report is fetching data instantly everywhere in prod.
6. The STRANGE thing that we have noticed that, when we submit the concurrent request, the ORACLE_PROCESS_ID in FND_CONCURRENT_REQUEST does not get populated. It is NULL. For all other request, there is process ID.