Fulfillment services -- High processor times

After a database upgrade from 9.2.0.8 to 11.2.0.3 and applying required patches to stay on extended support on EBS 11.5.10.2.

 Fulfillment services more than any other process seems to be processor bound and does not seem to cleanly go down after adstpall.sh is run.
Is this a known issue and if it is ,what do we need to do to reduce the processor time or/and make sure it goes down after an instance restart.

I have had to manually  set up the shutdown script to kill all Fulfillment services after a shutdown but that has not resolved the issue

of high processor time.