Qualified dividends are always included in taxable income (1040 line 15). The dividends may be "taxable" at a 0% tax rate, but they are still technically taxable. The calculation of taxable income does not take into consideration whether the 0% rate might apply. The rates are applied after the total taxable income is calculated. Is there any change in the tax on line 16 between the two returns?
For 2020 the 0% tax rate for qualified dividends and long-term capital gains applies if taxable income (1040 line 16) is up to $40,000 for single or married filing separately, $53,600 for head of household, or $80,000 for married filing jointly or qualifying widow(er). Note that it's based on taxable income, not total income or AGI.
