Did you report unemployment? Did you need to repay any premium tax credit?
There was a recent tax law change and up to 10,200 of unemployment is now non-taxable. Any over-payment of premium tax credit does not need to be paid back.
TurboTax is adjusting for this since the IRS does NOT want returns to be amended, they will adjust for the unemployment and premium heath credits on returns already filed.
TurboTax is adjusting the returns so that they will be accurate next year.
Look at schedule 1 for a subtraction to unemployment.