@VuN
You have improperly entered the expenses, so they are not offsetting the box 1 distribution. It could be that you are claiming a tuition credit, which means some of the tuition is no longer available to be applied to the 1099-Q. That would make some of the earnings (but usually not all) taxable.
If you know that you have enough expenses, just don't enter the 1099-Q (or delete it if you have entered it).
On form 1099-Q, instructions to the recipient reads: "Nontaxable distributions from CESAs and QTPs are not required to be reported on your income tax return. You must determine the taxability of any distribution."
