Long Term Capital Gains Taxed at Incorrect Rate (Too high)

I have some LT capital gains this year (Box E). Turbotax is charging me an effective tax rate of 21.8% on the gain when it should be 15% based off my tax bracket. Why would this be happening? This is happening on more than one transaction and makes a huge difference to the taxes I paid.

 

Assuming this is wrong, it is pretty annoying that I had to deduce this myself, as I was ready to pay even though the tax bill seemed much higher than I thought it should be, but I tested removing those LT gains and was able to back into the 21.8% rate.