Turbotax Recovery Rebate Credit 2021

Turbo Tax (CD at home) computed a $1,600 Recovery Rebate Credit and the form was electronically submitted to IRS. I just received a letter from the IRS stating they have corrected/make changes to my return in that the $1,600 was incorrect and apparently should/is zero there by reducing my refund?? How could this happen?

 

Makes me wonder about the overall accuracy of Turbo Tax's calculation!!

 

John [PII removed]

3/5/2022