You should review the education section of the program. You should also print the return, including the 8863 to see which student is listed twice. It sounds like the 1098-T's that were entered were allocated to the same student. Please check to see if you have both students listed in the education section and if they each report their own 1098-T.
Sign into your account and return
Click Federal on the left side-bar
Click Deductions & Credits along the top
Scroll down to Expenses & Scholarships and click Edit/Add
The next screen should resemble the screenshot. Both students should be listed. Click Edit for each student and review their reported expenses.