I had to withdrawal early from my 401k last year. I made sure to leave 30% in to cover the 20% tax and the additional 10% penalty. Turbo tax is saying I owe another 10%?

On my form 1099-R form, it was i paid 30% in federal income tax. Online it says i should be taxed 20% and then the additional 10% penalty. Why should i owe any more money?