Hi Mamoon,
Please check SE54 for the Job which is triggered on update assignment.
GRFNVC_PLUSG - Edit view Clusture > Plan activity for AC
GRAC_BRLP should have been configured, without which click on Update assignment will not work or trigger the job.
Also, implement the below Note in your system.
1837416
Hope this Information would be helpful!
Best Regards,
Shreya Gupta
