There are a few reasons why this may be happening:

• You entered Tuition amounts from the current year from a T2202A incorrectly. You should return to that slip and verify that you haven't made a keying error.
• You've entered your Tuition CarryForward amounts incorrectly.
• You imported your tax information using the CRA AutoFill service and this is the amount that CRA has in their records as your Provincial Tuition Carry Forward amount. If this is the case, you should contact CRA and verify if this figure is correct. It may be correct, but that is an extremely high amount of tuition costs incurred.