My tax guy is saying that I am taxed on the earnings in box 2 of my 1099-Q form

First time ever, we decided to pay someone else to do our taxes. We pay for our son's college out of his 529. Our tax guy says we owe taxes on box 2 of the 1099-Q. Says we pay taxes on just the earnings. For the first time this year we owe money to the fed because of this. My husband always used turbo tax before this. All of the other years we never paid taxes on the earnings of the 1099-Q. Is our tax guy correct?