Hi Gaurav,
The strange behavior is, it has updated the Reserved Quantity. Your screenshot displays only one order with difference material, can you check whether this is a normal for other orders as well. If this is a common issue, then OSS is the final option.
May be you have already checked the selection variant. Also check your selection variant in IW13, like pass only the order number and execute without any dates etc.
Regards
Terence
