Why am I being charged $20 for federal e-filing?

I bought TurboTax Premiere with these features:

 

Premier
Includes 5 federal e-files
Includes 1 state download
State e-file sold separately

 

I e-filed one federal return already, at no cost to me.

Now I am about to file the second one, and I am being asked to pay $20.

(It's actually $40:  $20 for state and $20 for federal.)

I understand the $20 for state, but why am I being charged an additional $20 for state?