I received a CP3219A (Notice of Deficiency - Proposed Tax Increase. I used TurboTax Deluxe that year. I don't know if I should agree or disagree with this notice. I now owe them an additional $3,715. Do I agree or disagree? What is TurboTax's responsibility here? How did this error occur if I filed everything correctly and it was accepted in 2018?
