Hello-
I had the same problem and for me it was an error on my part but easily done and difficult to find after the fact.
When you add a 1099-INT form, if box 17 (of the 1099-INT) does not have a value populated, Turbo Tax will ask you to enter state tax withheld on the Interest. For myself, I thought box 17 was referring to my W2 so I entered my state tax withheld listed in box 17 from my W2. This ends up doubling your state tax withheld. Unfortunately, TurboTax does not pick this up as an anomaly, which it should. Anyhow, the fix is to delete the 1099-INT and reenter it and if your 1099-INT box 17 has no values, enter 0 and you should be good to go.
I cannot get back the time I spent trying to figure out why my state tax was over stated so I hope this helps someone from spending their afternoon being puzzled. I will eat my crow and admit user error but Turbo Tax should be better at picking up mistakes.
