It is unusual, but it's simply what 2023 Schedule M1M, Income Additions and Subtractions requires.
According to Line 33 – Subtraction for one-time refund for tax year 2021 in the instructions linked above:
If you received a direct tax rebate payment for the one-time refund for tax year 2021, include the amount you received on line 33. You must have included the payment in federal adjusted gross income to subtract it on line 33.
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