Where is tuition expense entered? The "Jump to 1098-T" link brings me to a section that displays Tuition as $0, the help says tuition was entered "earlier"... but where?

There should be an "edit" button next to it but if that doesn't work you might have to delete the tuition information first by following these instructions: How do I view and delete forms in TurboTax Online? Look for 1098-T Wks.

Other option to get to Expenses and Scholarships (Form 1098-T):

1. Login to your TurboTax Account 
2. Click "Federal" from the left side of your screen
3. Click “Deductions &Credits” on the top
4. Scroll down to "Education" and click "Show more"
5. Click "Start " next to "Expenses and Scholarships (Form 1098-T)"