This is a serious bug. In my case after rounding thousands of individual transactions, I ended up with 21% more short term gains from crypto (Box C) reported on Schedule D than were reported in the 1099-B summary table. It's even more deceiving because the UI only shows the 1099-B summary, not the incorrectly rounded it actually puts in Schedule D.
This violates both the accuracy and the maximum tax savings guarantees. https://turbotax.intuit.com/corp/guarantees/.
Incredible that this bug has been present for 2 tax cycles and TurboTax still ignores it.
