I haven't had to research the new "high school" rules so maybe something addresses this.  In general, 1099-Q forms are issued either to the account owner or to the account beneficiary depending on how the funds were disbursed.  Could it be that the 1099-Q was issued in the child's name/SSN?  If so, I think that would likely make it taxable on the child's 1040.  If not, check your data entry to make sure you're not accidentally marking it as such.

If it's any consolation, I agree with your conclusion!

Rick