gstr 9 itc mismatch

One of my supplier issued a credit note to me in march 2018 and entered same in his gstr1 of march 2018 but he didn't sent me that cn.
So that cn was not entered in my gstr3b and account books of fy 1718.

I received that cn in july 2018 and entered that cn in my gstr3b and accounts books in fy 1819.

While filing gstr9 for fy 1718 , this is creating a difference in gstr2a and gstr3b itc amount.

Please help on handling this problem