Get your taxes done using TurboTax

Go to Forms or do an export of the return to PDF with all supporting worksheets and see what is happening on the "Qualified Dividends and Capital Gain Tax Worksheet" that will show you step by step the calculations and why this is triggering a higher than expected rate.  6/25 = 24% sounds like it's getting the 20% rate plus the 3.8% investment income tax.