It may have downloaded CA because you used CA last year....
1) You aren't committed to use the CA one as your one free state, unless you actually use it. You can try to load WI too when you get to the state section (If the WI software is actually ready for downloading) .
BUT
2) You need both state tax forms in the year you moved...(if you meant December of 2020 and not 2019), so it doesn't make any difference which one is the free one...you'll have to pay for the other state to prepare part-year tax returns for both states anyhow.
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*