I have thoroughly checked that there are no errors in manual entry. And, as I mentioned in the post, the manual entry total gain matches the imported transactions' total gain to the penny. So, there is no room for error in the entry part. The difference is in how TurboTax computes the total capital gain. This exact thing happened to me in the previous tax year (2020) as well and I just didn't notice.
It's even more unlikely that I made a similar manual entry error (I don't even remember if I used manual entry last year or not; could've been imported transactions for all the forms) that would result in a similar error for two different years with completely different forms and numbers.
I don't get access to Schedule D until after I file. Is there a way to see Schedule D before filing? I am using online version of TurboTax. If only I could see the Schedule D and the Qualified Dividends and Capital Gains Tax Worksheet, I'd be able to investigate further.
