Arithmetical Error in BP u/s 143 (1)(a)

I received an intimation u/s 143 (1)(a) for an arithmetic error in schedule BP via mail on 31.12.2019.

1)In schedule BP ,SI No.A.13 Profit or loss after adjustment for depreciation (10+11-12iii) and the sum of amount entered in SI.No.10+11-12iii are inconsistent.


2) In schedule BP, SI No.A.35 Income (13+26-34) and the sum of amount entered in SI.No.A13+A26-A34 are inconsistent.

HOWEVER i checked the values in the return and there is perfect match.
there is no arithmetic error.

I prepare the return using excel utility where all items in schedule BP were calculated automatically.

what is the reason for such intimation? ?