IRS Letter 6475 Not Matching TurboTax

We received $4200 in 2021, which I thought corresponded to me, my spouse, and my mother (our dependent - fully qualified).  My mother died in Sep 2020 and we included all expenses we spent for her to that point in our 2020 Tax Return; also indicated she passed in Sep 2020 on the tax return.

 

Now, TurboTax only calculated $2800, counting only me and my spouse.

 

Which one is correct?