https://www.irs.gov/instructions/i1040gi#en_US_2023_publink24811vd0e10721
Under: 2023 Tax Computation Worksheet—Line 16
The calculation done in turbotax is incorrect when reviewing the formula described in:
Section B—Use if your filing status is Married filing jointly or Qualifying surviving spouse. Complete the row below that applies to you.
There are like 7 different ways to calculate the tax.
It depends what kind of income you have. Even though the full amount shows up in the total income on the 1040 line 7, if you have capital gains or qualified dividends the tax is not taken from the tax table but is calculated separately from Schedule D. The tax will be calculated on the Qualified Dividends and Capital Gain Tax Worksheet. It does not get filed with your return. In the online version you need to save your return as a pdf file and include all the worksheets to see it.
For the Desktop version you can switch to Forms Mode and open the worksheet to see it. Click Forms in the upper right (upper left for Mac) and look through the list and open the Qualified Dividends and Capital Gain Tax Worksheet. And you will need to use this IRS worksheet on page 15.
https://www.irs.gov/pub/irs-pdf/i1040tt.pdf
Nobody has mentioned it before. It can be convoluted to figure the tax. When I checked my Joint return it figured the tax right using the Qualified Dividends and Capital Gain Tax Worksheet and the section B table.