In addition to what VolvoGirl said, if you received a refund in 2022 from your 2021 state tax return, and you claimed an itemized deduction for state income tax on your 2021 federal tax return, the amount of state tax that you paid in 2022 affects the calculation of how much of your 2021 state refund has to be reported as taxable income on your 2022 federal tax return. For this purpose, the 2021 state overpayment that you applied to your 2022 state tax is considered a state refund, even though it was not actually refunded to you.
You are not "declaring it twice." The amount of 2021 state tax that you paid in 2022 is not being applied to your 2022 state tax. It's only being used for calculations involved in your 2022 federal tax return.
