What if we lost reservation on a line

Once in a while I have noticed that Order Line lost reservation on a booked order line even when delivery details has released_status = staged.
Now because of lost of reservation , reserved qty column is null in sales order form as well as when I check the data  in table mtl_reservation there is no data with
demand_source_line_id = order_line_id. 

Due to lost reservation on order line, stock that was earlier reserved for this particular line now picked up by another sales orde line , that results in confusion and delay .

NOW one quick fix for such issue is Navigate to order >> order lines >> TOOLS
select SCHEDULING  >> RESERVATIONS DETAILS and populate the qty that you have lost in the quantity field ( in am assuming we have stock , with out stock we will not be able to RESERVE quantity ) , Once done we are ready for ship confirm.

Hope that helps.