Hi Deepak,
This sounds like it may necessitate a support case.
It sounds to me that there may be a conflict of timing between these two policies. How are you serializing these two policies? What is the event or task trigger for each of them?
You can export the IME zip file, and include it here and let us know the names of both policies and we can have a look.
However, as said, I feel it would be better analyzed via a support case.
Regards,
Sagi