Why does my tax refund go down after applying the Education nonrefundable credit?

The Refund Meter can decrease not due to an entry you just made, but also at the end of a section

Click this link for more info on Education Credits.

The Earned Income credit is added to the refund meter as you enter your income and personal information.

As you lower your taxable income with educational deductions, you may lower the amount of your Earned income Credit, thus lowering the dollar amount you see on the refund meter.

The refund meter will not be completely accurate until you have entered all of your information including all income and deductions.

This link gives info on the Qualifications for Earned Income Credit.