Credit Note ITC not showing in GSTR-2B

We issued 2 credit notes in August and put in the details in the IFF. The IFF summary shows a negative tax liability. But that ITC is not showing in the GSTR-2B of August or the September. It is only showing the ITC from some purchases. How to claim that ITC?

The value of the credits notes is higher than the total sales in the quarter. So the GSTR-3B should also show negative value, but it is showing "0". Where does that ITC goes?