WIP Assemby completion did not backflush Assembly Pull Components

 Hi,  I have a job of 100 quantities which was completed in stages. In the last stage of 10 quantities 

Wip assembly completion happened successfully but against that completion no material was issued. 

All the components have supply type of Assembly Pull. 

I have checked everything there is no pending or stuck transaction anywhere in the system. 

Can someone has any idea was backflush was not triggered by wip assembly completion. 

In the discrete job quantities required for the final 10 assembly is showing as open. 

There is enough stock in the subinventory, also negative is allowed. 

please someone advise.

Thanks in advance