The tuition credit is non-refundable, so you only get the credit if you have taxes payable. It will never be used to give you a refund. What may have happened in previous years is that you may have accidentally gotten the Working
Income Tax Benefit (WITB). This is a refundable tax credit for people who
work, but don’t make very much, and it adds quite a bit to a refund. However, students are usually not eligible for
this credit, so when you tell TurboTax that you have tuition, then normally the WITB is
removed.
If you did your previous year's taxes with TurboTax, you may want to contact our phone support as they can help you check what was different in your previous year's returns compared to this year: https://turbotax.community.intuit.ca/replies/3152013
