An update on this: I have completed my data entry. I entered my 1099-NEC income during the interview for "Income from Form 1099-NEC" under the "1099-MISC and Other Common Income" section. This is also what I did in 2023. For both years, this was income from a consulting business, and as best I can tell I entered it the same way both years.
Having completed the entire 2024 interview, in the 2023 column my 2023 1099-NEC income shows up on two lines: the "1099-MISC and Other Common Income" line and the "Business income and Expenses" line. In contrast, the 2024 1099-NEC income shows up only in one place, that being on the "Business income and Expenses" line.
Checking the Forms View, I see that TurboTax has completed the Schedule C for my 1099-NEC income, so the correct data will be presented to the IRS. The inconsistent way 2023 and 2024 income are shown in the 2024 Income Summary still puzzles me, but it doesn't seem to affect the accuracy of the return.
