Yes, the health insurance is taxable if the amount in Box 5 exceeds the amount in Box 1. TurboTax is only going to go by what is reported on Form 1098-T. If you feel this is wrong, you need to take this up with the university.
If the health insurance is a benefit of employment, then ask the university why it is reported on the 1098-T.
Is the amount in Box 5 more than the amount in Box 1? If not, then you are not being taxed on this amount.
