NC529 Plan

In 2021, I withdrew $5500 from each of the NC 529 accounts that I set up for my grandchildren to pay for their K-12 education. I am listed as the participant on the account and each of them is listed as beneficiary on their individual accounts. I deposited the money in my checking account, had a cashier's check made out to my son, who then paid the tuition at the school. However, the 1099-Q form I received shows me as the recipient, $2242 as earnings, the box is checked that says 'recipient is not beneficiary',  and it is resulting in me owing more taxes. My understanding of NC 529 is that if it's used for K-12 tuition it should be taxable. Is it possible I made the withdrawal incorrectly? If so, how can I get this corrected?