What do I do if TurboTax is incorrectly calculating the state refund amount?

Please clarify,

are you referring to the amount that was refunded from the state regarding the 2019 Tax Year return (which you received in 2020) OR the amount TurboTax is calculating on the State 2020 Tax Year return? 

to get the right taxable amount for a 2019 state tax refund, you must

• have itemized in 2019
• not checked the sales tax box on Schedule A Line 5a
• be able to tell TurboTax how much sales tax you could have reported if you had chosen that option.