"Was a full-time student in 2024" appears as an option for one dependent child but not the other. How can I select "Was a full-time student in 2024" for both children?

We'd love to help you complete your tax return, but need more information. Can you please clarify the ages of the children?

You don't get that if the birthdate indicates they are under 19.

A child can be a "qualifying child" dependent if He is under age 19, or under 24 if a full time student for at least 5 months of the year, or is totally & permanently disabled.

So, student status doesn't matter if he is under 19, at that point in the interview.

Later, at educational expenses, you will be given a chance to label his student status, for purposes of claiming the education credit.